G01 - Corrosion of Metals
The scope of the Committee shall be the promotion of knowledge, the stimulation of research, the collection of engineering data, and the development of standard test methods, practices, guides, classifications, specifications and terminology relating to corrosion and methods for corrosion-protection of metals. The work of this Committee will be coordinated with other ASTM Committees and other organization having mutual interest.
Corrosion of Metals
The scope of the Committee shall be the promotion of knowledge, the stimulation of research, the collection of engineering data, and the development of standard test methods, practices, guides, classifications, specifications and terminology relating to corrosion and methods for corrosion-protection of metals. The work of this Committee will be coordinated with other ASTM Committees and other organization having mutual interest.
General Information
SIGNIFICANCE AND USE
4.1 This test method provides a quantitative measure of the susceptibility to intergranular corrosion of Al-Mg and Al-Mg-Mn alloys. The nitric acid dissolves a second phase, an aluminum-magnesium intermetallic compound (βAl-Mg), in preference to the solid solution of magnesium in the aluminum matrix. When this compound is precipitated in a relatively continuous network along grain boundaries, the effect of the preferential attack is to corrode around the grains, causing them to fall away from the specimens. Such dropping out of the grains causes relatively large mass losses of the order of 25 mg/cm2 to 75 mg/cm2 (160 mg/in.2 to 480 mg/in.2), whereas, samples of intergranular-resistant materials lose only about 1 mg/cm2 to 15 mg/cm2 (10 mg/in.2 to 100 mg/in.2). When the βAl-Mg compound is randomly distributed, the preferential attack can result in intermediate mass losses. Metallographic examination is required in such cases to establish whether or not the loss in mass is the result of intergranular attack.
4.2 The precipitation of the second phase in the grain boundaries also gives rise to intergranular corrosion when the material is exposed to chloride-containing natural environments, such as seacoast atmospheres or sea water. The extent to which the alloy will be susceptible to intergranular corrosion depends upon the degree of precipitate continuity in the grain boundaries. Visible manifestations of the attack may be in various forms such as pitting, exfoliation, or stress-corrosion cracking, depending upon the morphology of the grain structure and the presence of sustained tensile stress.3
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1.1 This test method, also known as the Nitric Acid Mass Loss Test (NAMLT), covers a procedure for constant immersion intergranular corrosion testing of 5XXX series aluminum alloys.
1.2 This test method is applicable only to wrought products.
1.3 This test method covers type of specimen, specimen preparation, test environment, and method of exposure.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard5 pagesEnglish language
- Standard5 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method was originally developed for research and development purposes; however, it is referenced, in specific material specifications, as applicable for evaluating production material (refer to Section 14 on Precision and Bias).
5.2 Use of this test method provides a useful prediction of the exfoliation corrosion behavior of these alloys in various types of outdoor service, especially in marine and industrial environments.5 The test solution is very corrosive and represents the more severe types of environmental service, excluding, of course, unusual chemicals not likely to be encountered in natural environments.
5.3 The exfoliation ratings were arbitrarily chosen to illustrate a wide range in resistance to exfoliation in this test. However, it remains to be determined whether correlations can be established between EXCO test ratings and realistic service conditions for a given alloy. For example, it has been reported6 that samples of Al-Zn-Mg-Cu alloys rated EA or P in a 48 h EXCO test did not develop more than a slight amount of incipient exfoliation (EA) during six- to nine-year exposures to seacoast atmospheres, whereas, ED rated materials in most cases developed severe exfoliation within a year in the seacoast atmosphere.
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1.1 This test method covers a procedure for constant immersion exfoliation corrosion (EXCO) testing of high-strength 2XXX (see Note 2) and 7XXX series aluminum alloys.
Note 1: This test method was originally developed for research and development purposes; however, it is referenced, in specific material specifications, as applicable for evaluating production material (refer to Section 14 on Precision and Bias).
Note 2: Some Al-Cu-Li alloys are registered in the 2xxx family. This test method has been reported as non representative of performance in outdoor atmospheres for various Al-Cu-Li alloys in both as-quenched and artificially aged tempers.2
1.2 This test method applies to all wrought products such as sheet, plate, extrusions, and forgings produced from conventional ingot metallurgy process.
1.3 This test method can be used with any form of specimen or part that can be immersed in the test solution.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method provides a reliable prediction of the exfoliation corrosion behavior of Al-Mg alloys in marine environments.4,5,6 The test is useful for alloy development studies and quality control of mill products such as sheet and plate.
SCOPE
1.1 This test method covers a procedure for continuous immersion exfoliation corrosion testing of 5XXX series aluminum-magnesium alloys containing 2.0 % or more magnesium.
1.2 This test method applies only to wrought products.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard5 pagesEnglish language
- Standard5 pagesEnglish language
SIGNIFICANCE AND USE
4.1 The intent of this practice is to indicate standard welded specimens and welding procedures for evaluating the SCC characteristics of weldments in corrosive environments. The practice does not recommend the specific corrosive media that may be selected by the user depending upon the intent of his investigation. Specific corrosive media are included in Practices G35, G36, G37, and G44. Other environments can be used as required.
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1.1 This practice covers procedures for the making and utilization of test specimens for the evaluation of weldments in stress-corrosion cracking (SCC) environments.
1.2 Test specimens are described in which (a) stresses are developed by the welding process only, (b) stresses are developed by an externally applied load in addition to the stresses due to welding, and (c) stresses are developed by an externally applied load only with residual welding stresses removed by annealing.
1.3 This practice is concerned only with the welded test specimen and not with the environmental aspects of stress-corrosion testing. Specific practices for the bending and loading of test specimens, as well as the stress considerations involved in preparation of C-rings, U-bend, bent-beam, and tension specimens are discussed in other ASTM standards.
1.4 The actual stress in test specimens removed from weldments is not precisely known because it depends upon the level of residual stress from the welding operation combined with the applied stress. A method for determining the magnitude and direction of residual stress which may be applicable to weldment is described in Test Method E837. The reproducibility of test results is highly dependent on the preparation of the weldment, the type of test specimen tested, and the evaluation criteria used. Sufficient replication should be employed to determine the level of inherent variability in the specific test results that is consistent with the objectives of the test program.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (For more specific safety hazards information, see Section 7.)
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 In the absence of water, the crude oil is noncorrosive. However, trace amounts of water and sediment have the potential to create corrosive situations during crude oil handling or transport if such materials accumulate and persist on steel surfaces. Test Methods D473 and D4006 provide methods for determination of the water and sediment content of crude oil.
5.2 The potential for a corrosive situation to develop during the handling and transport of crude oil that contains water can be determined by a combination of three properties (Fig. 1) (1)6: the type of emulsion formed between oil and water, the wettability of the steel surface, and the corrosivity of water phase in the presence of oil.
FIG. 1 Predicting Influence of Crude Oil on the Corrosivity of Aqueous Phase
5.3 Water and oil are immiscible but, under certain conditions, they can form emulsion. There are two kinds of emulsion: oil-in-water (O/W) and water-in-oil (W/O). W/O emulsion (in which oil is the continuous phase) has low conductivity and is thus less corrosive; whereas O/W (in which water is the continuous phase) has high conductivity and, hence, is corrosive (2) (see ISO 6614). The percentage of water at which W/O converts to O/W is known as the emulsion inversion point (EIP). EIP can be determined by measuring the conductivity of the emulsion. At and above the EIP, a continuous phase of water or free water is present. Therefore, there is a potential for corrosion.
5.4 Whether water phase can cause corrosion in the presence of oil depends on whether the surface is oil-wet (hydrophobic) or water-wet (hydrophilic) (1, 3-5). Because of higher resistance, an oil-wet surface is not susceptible to corrosion, but a water-wet surface is. Wettability can be characterized by measuring the contact angle or by evaluating the tendency of water to displace oil from a multi-electrode array by measuring the resistance (or conductors) between the electrodes (spreading methodology).
5.4.1 In the con...
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1.1 This guide covers some generally accepted laboratory methodologies that are used for determining emulsion forming tendency, wetting behavior, and corrosion-inhibitory properties of crude oil.
1.2 This guide does not cover detailed calculations and methods, but rather covers a range of approaches that have found application in evaluating emulsions, wettability, and the corrosion rate of steel in crude oil/water mixtures.
1.3 Only those methodologies that have found wide acceptance in the industry are considered in this guide.
1.4 This guide is intended to assist in the selection of methodologies that can be used for determining the corrosivity of crude oil under conditions in which water is present in the liquid state (typically up to 100 °C). These conditions normally occur during oil and gas production, storage, and transportation in the pipelines.
1.5 This guide is not applicable at higher temperatures (typically above 300 °C) that occur during refining crude oil in refineries.
1.6 This guide involves the use of electrical currents in the presence of flammable liquids. Awareness of fire safety is critical for the safe use of this guide.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide10 pagesEnglish language
- Guide10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This guide provides three methods for determining the suitability of a buried steel tank to be upgraded with cathodic protection.
4.2 This guide may be used to assess any UST, including non-regulated USTs.
4.3 This guide provides three alternative methods but does not recommend any specific method or application. The responsibility for selection of a method rests with the user.
4.4 This guide has specific suggestions for vendor provided information which should be requested and reviewed by the user.
SCOPE
1.1 This guide covers procedures to be implemented prior to the application of cathodic protection for evaluating the suitability of a tank for upgrading by cathodic protection alone.
1.2 Three procedures are described and identified as Methods A, B, and C.
1.2.1 Method A—Noninvasive with primary emphasis on statistical and electrochemical analysis of external site environment corrosion data.
1.2.2 Method B—Invasive ultrasonic thickness testing with external corrosion evaluation.
1.2.3 Method C—Invasive permanently recorded visual inspection and evaluation including external corrosion assessment.
1.3 This guide presents the methodology and the procedures utilizing site and tank specific data for determining a tank’s condition and the suitability for such tanks to be upgraded with cathodic protection.
1.4 While this guide provides minimum procedures for assessing a tank's condition, this guide does not provide minimum installation procedures or requirements for upgrades of the tank by cathodic protection.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide10 pagesEnglish language
- Guide10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This practice provides a controlled corrosive environment that has been utilized to produce relative corrosion information.
4.2 The primary application of the data from this practice is to evaluate the performance of metallic materials for use in soil environments.
4.3 This practice may not duplicate all field conditions and variables such as stray currents, microbiologically influenced corrosion, non-homogeneous conditions, pollutants in the soil, and long cell corrosion. The reproducibility of results in the practice is highly dependent on the type of specimen tested and the evaluation criteria selected as well as the control of the operating variables. In any testing program, sufficient replicates should be included to establish the variability of the results.
4.4 Structures and components may be made of several different metals; therefore, the practice may be used to evaluate galvanic corrosion effects in soils (see Guide G71).
4.5 Structures and components may be coated with sacrificial or noble metal coatings, which may be scratched or otherwise rendered discontinuous (for example, no coating on the edges of metal strips cut from a wide sheet). This test is useful to evaluate the effect of defective metallic coatings.
4.6 Structures and components may be coated or jacketed with organic materials (for example, paints and plastics), and these coatings and jackets may be rendered discontinuous. The test is useful to evaluate the effect of defective or incompletely covering coatings and jackets.
Note 1: The corrosivity of soils strongly depends on soluble salt content (related parameters are chemistry and soil resistivity, see Test Methods G57 and G187), acidity or alkalinity (measured by soil pH, see Test Method G51), Temperature, and oxygen content (loose, for example, sand, or compact, for example, clay, soils are extreme examples, see Test Method G200 – oxidation-reduction potential). The manufacturer, supplier, or user, or combination the...
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1.1 This practice covers procedures for conducting laboratory corrosion tests in soils to evaluate the potential for corrosion attack on engineering materials in soils. The test is conducted under laboratory ambient temperature unless the effect of temperature is being evaluated. This practice does not include provisions for microbiological influenced corrosion (MIC) testing, nor its influence on results.
1.2 This practice covers specimen selection and preparation, test environments, evaluation, and reporting of test results.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard5 pagesEnglish language
- Standard5 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The resistivity of the surrounding soil environment is a factor in the corrosion of underground structures. High resistivity soils are generally not as corrosive as low resistivity soils. The resistivity of the soil is one of many factors that influence the service life of a buried structure. Soil resistivity may affect the material selection and the location of a structure.5
5.2 Soil resistivity is of particular importance and interest in the corrosion process because it is basic in the analysis of corrosion problems and the design of corrective measures.
5.3 The test method is focused to provide an accurate, expeditious measurement of soil resistivity to assist in the determination of a soil’s corrosive nature. Test Method G57 emphasizes an in situ measurement commonly utilized in the design of a buried structures’ corrosion control (cathodic protection systems’ ground bed design, and so forth), but also includes information and procedures on a four-pin soil box method. The two-electrode soil box method is an accurate and more expeditious method than the four-pin soil box and often complements the four-pin, in situ soil resistivity method.
5.4 The saturated soil resistivity determined by this test method does not necessarily indicate the minimum soil resistivity.
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1.1 This test method covers the equipment and procedures for the measurement of soil resistivity, for soil samples removed from the ground, for use in the assessment and control of corrosion of buried structures.
1.2 Procedures allow for this test method to be used in the field or in the laboratory.
1.3 The test method procedures are for the resistivity measurement of soil samples in the saturated condition and in the as-received condition.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Soil resistivity values are reported in ohm-centimeter.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and to determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
4.1 Axially loaded tension specimens provide one of the most versatile methods of performing a stress-corrosion test because of the flexibility permitted in the choice of type and size of test specimen, stressing procedures, and range of stress levels.
4.2 The uniaxial stress system is simple; hence, this test method is often used for studies of stress-corrosion mechanisms. This type of test is amenable to the simultaneous exposure of unstressed specimens (no applied load) with stressed specimens and subsequent tension testing to distinguish between the effects of true stress corrosion and mechanical overload (2). Additional considerations in regard to the significance of the test results and their interpretation are given in Sections 6 and 10.
4.3 Wide variations in test results may be obtained for a given material and specimen orientation with different specimen sizes and stressing procedures. This consideration is significant especially in the standardization of a test procedure for interlaboratory comparisons or quality control.
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1.1 This practice covers procedures for designing, preparing, and using ASTM standard tension test specimens for investigating susceptibility to stress-corrosion cracking. Axially loaded specimens may be stressed quantitatively with equipment for application of either a constant load, constant strain, or with a continuously increasing strain.
1.2 Tension test specimens are adaptable for testing a wide variety of product forms as well as parts joined by welding, riveting, or various other methods.
1.3 The exposure of specimens in a corrosive environment is treated only briefly because other standards are being prepared to deal with this aspect. Meanwhile, the investigator is referred to Practices G35, G36, G37, and G44, and to ASTM Special Technical Publication 425 (1).2
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard6 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method provides controlled environments which are utilized to produce corrosion of metal, metal-coated, or nonmetallic-coated smooth or deformed shank driven fasteners in contact with treated wood exposed to the given test environments. The test method provides information that can be used to evaluate the corrosion resistance of metal, metal-coated, or nonmetallic-coated smooth or deformed shank driven fasteners in contact with different chemical wood treatments.
5.2 The results shall be used for comparative purposes only and they shall not be correlated to exposure time in natural environments.
5.3 The reproducibility of results in these types of tests is highly dependent on the type of samples tested and the evaluation criteria selected, as well as the control of the operating variables.
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1.1 This test method covers and focuses on the corrosion resistance of metal, metal-coated, and nonmetallic-coated smooth and deformed shank driven fasteners in contact with treated wood in exterior or high moisture exposure applications using comparative tests with control fastener specimens of standardized benchmarks. This test method may be used for preservative-treated wood.
1.2 This test method describes the apparatus, procedure, and conditions required to maintain test environments for the Cyclic Fog Test and the Steady State Moisture Test.
1.3 This test method describes the types of test samples, lists exposure periods, and gives guidance on interpretation of results.
1.4 Until experience is gained comparing laboratory-to-laboratory results with this test method, comparisons of fasteners, coatings, materials, or preservatives shall be made only within the results of the same test.
1.5 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard6 pagesEnglish language
SIGNIFICANCE AND USE
4.1 Information on pH of soil is used as an aid in evaluating the corrosivity of a soil environment. Some metals are more sensitive to the pH of their environment than others, and information on the stability of a metal as a function of pH and potential is available in the literature.3
SCOPE
1.1 This test method covers a procedure for determining the pH of a soil in corrosion evaluations. The principle use of the test is to supplement soil resistivity measurements and thereby identify conditions under which the corrosion of metals in soil may be accentuated (see G57 – 78 (2012)).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
3.1 This test method can be utilized to verify the performance of polarization resistance measurement equipment including reference electrodes, electrochemical cells, potentiost- ats, scan generators, and measuring and recording devices. The test method is also useful for training operators in sample preparation and experimental techniques for polarization resistance measurements.
3.2 Polarization resistance can be related to the rate of general corrosion for metals at or near their corrosion potential, Ecorr. Polarization resistance measurements are an accurate and rapid way to measure the general corrosion rate. Real-time corrosion monitoring is a common application. The technique can also be used as a way to rank alloys, inhibitors, and so forth in order of resistance to general corrosion.
3.3 In this test method, a small potential scan, ΔE(t), defined with respect to the corrosion potential (ΔE = E – Ecorr), is applied to a metal sample. The resultant currents are recorded. The polarization resistance, RP, of a corroding electrode is defined from Eq 1 as the slope of a potential versus current density plot at i = 0 (1-4):3
The current density is given by i. The corrosion current density, icorr, is related to the polarization resistance by the Stern-Geary coefficient, B. (3),
The dimension of Rp is ohm-cm2, icorr is muA/cm2, and B is in V. The Stern-Geary coefficient is related to the anodic, ba, and cathodic, bc, Tafel slopes in accordance with Eq 3.
The units of the Tafel slopes are V. The corrosion rate, CR, in mm per year can be determined from Eq 4 in which EW is the equivalent weight of the corroding species in grams and ρ is the density of the corroding material in g/cm3.
Refer to Practice G102 for derivations of the above equations and methods for estimating Tafel slopes.
3.4 The test method may not be appropriate to measure polarization resistance on all materials or in all environments. See 8.2 for a discussi...
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1.1 This test method covers an experimental procedure for polarization resistance measurements which can be used for the calibration of equipment and verification of experimental technique. The test method can provide reproducible corrosion potentials and potentiodynamic polarization resistance measurements.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
3.1 These test methods provide a reliable means for predicting the inhibiting or corrosive properties of admixtures to be used in concrete.
3.2 The total integrated (coulombs) current is calculated to provide an indication of the corrosion that occurs due to the macrocell corrosion.
3.3 These test methods are useful for development studies of corrosion inhibitors to be used in concrete.
3.4 These test methods have been used elsewhere with good agreement between corrosion as measured by these test methods and corrosion damage on the embedded steel (1-4).4 These test methods might not properly rank the performance of different corrosion inhibitors, especially at concrete covers over the steel less than 40 mm (1.5 in.) or water-to-cement ratios above 0.45. The concrete mixture proportions and cover over the steel are chosen to accelerate chloride ingress. Some inhibitors might have an effect on this process, which could lead to results that would differ from what would be expected in actual use (5).
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1.1 These test methods cover a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. These test methods can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures in a chloride environment.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard6 pagesEnglish language
- Standard6 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The availability of a standard procedure, standard material, and standard plots should allow the investigator to check his laboratory technique. This practice should lead to electrochemical impedance curves in the literature which can be compared easily and with confidence.
5.2 Samples of a standard ferritic type 430 stainless steel (UNS 430000) used to obtain the reference plots are available for those who wish to check their equipment. Suitable resistors and capacitors can be obtained from electronics supply houses.
5.3 This test method may not be appropriate for electrochemical impedance measurements of all materials or in all environments.
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1.1 This practice covers an experimental procedure which can be used to check one's instrumentation and technique for collecting and presenting electrochemical impedance data. If followed, this practice provides a standard material, electrolyte, and procedure for collecting electrochemical impedance data at the open circuit or corrosion potential that should reproduce data determined by others at different times and in different laboratories. This practice may not be appropriate for collecting impedance information for all materials or in all environments.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard11 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This test method provides a means for assessing corrosion-inhibiting concrete admixtures.
4.2 This test method is useful for development of admixtures intended to reduce corrosion of reinforcing steel in concrete.
4.3 This test method is useful in determining the corrosivity of admixtures toward steel reinforcing if the admixture sample is compared to a control without admixtures.
4.4 Good performance, a reduction in corrosion rate versus chloride alone by at least one order of magnitude in this test, is a strong indication that an admixture is a corrosion inhibitor. However, poor performance requires additional testing to determine if the admixture improves corrosion resistance.
4.5 This test method shall not be used to predict performance in the field.
4.6 The filtering process makes this test not suitable for the evaluation of emulsions.
SCOPE
1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for emulsions.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard6 pagesEnglish language
- Standard6 pagesEnglish language
SIGNIFICANCE AND USE
3.1 Moist air containing sulfur dioxide quickly produces easily visible corrosion on many metals in a form resembling that occurring in industrial environments. It is therefore a test medium well suited to detect pores or other sources of weakness in protective coatings and deficiencies in corrosion resistance associated with unsuitable alloy composition or treatments.
3.2 The results obtained in the test should not be regarded as a general guide to the corrosion resistance of the tested materials in all environments where these materials may be used. Performance of different materials in the test should only be taken as a general guide to the relative corrosion resistance of these materials in moist SO2 service.
SCOPE
1.1 This practice covers the apparatus and procedure to be used in conducting qualitative assessment tests in accordance with the requirements of material or product specifications by means of specimen exposure to condensed moisture containing sulfur dioxide.
1.2 The exposure conditions may be varied to suit particular requirements and this practice includes provisions for use of different concentrations of sulfur dioxide and for tests either running continuously or in cycles of alternate exposure to the sulfur dioxide containing atmosphere and to the ambient atmosphere.
1.3 The variant of the test to be used, the exposure period required, the type of test specimen, and the criteria of failure are not prescribed by this practice. Such details are provided in appropriate material and product purchase specifications.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For a specific warning statement, see 4.3.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard6 pagesEnglish language
SIGNIFICANCE AND USE
5.1 Domestic wastewater headspace environments are corrosive due to the presence of sewer gases and sulfuric acid generated during the biogenic sulfide corrosion process.5 This operating procedure provides an accelerated exposure to sewer gases and concentration of sulfuric acid commonly produced by bacteria within these sewer environments.6
5.2 The results obtained by the use of this practice can be a means for estimating the protective barrier qualities of a protective coating or lining for use in severe sewer conditions.
5.3 Some protective coatings or linings may not withstand the exposure temperature specified in this practice but have demonstrated satisfactory performance in actual sewer exposures, which are at lower temperatures.
SCOPE
1.1 This practice covers the basic apparatus, procedures, and conditions required to create and maintain the severe wastewater analysis testing apparatus used for testing a protective coating or lining.
1.2 This apparatus may simulate the pertinent attributes of a typical domestic severe wastewater headspace (sewer) environment. The testing chamber comprises two phases: (1) a liquid phase containing a prescribed acid and saline solution, and (2) a vapor phase consisting of air, humidity, and concentrated sewer gas (Note 1). The temperature of the test chamber is elevated to create accelerated conditions and reaction rates.
Note 1: For the purposes of this practice, sewer gas is composed of hydrogen sulfide, carbon dioxide, and methane gas.
1.3 Caution—This practice can be extremely hazardous. All necessary precautions need to be taken when working with sewer gas, sulfuric acid, and a glass tank. It is highly recommended that a professional testing laboratory experienced in testing with hydrogen sulfide, carbon dioxide, and methane gases perform this practice.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 8 on Hazards.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
4.1 Polythionic acids are chemically described as H2SxO6, where x is usually 3, 4, or 5 (1)3 though can be more than 50 (2). These acid environments provide a way of evaluating the resistance of stainless steels and related alloys to intergranular stress corrosion cracking. Failure is accelerated by the presence of increasing amounts of intergranular precipitate. Results for the polythionic acid test have not been correlated exactly with those of intergranular corrosion tests (Test Methods G28). Also, this test may not be relevant to stress corrosion cracking in chlorides or caustic environments.
4.2 The polythionic acid environment may produce areas of shallow intergranular attack in addition to the more localized and deeper cracking mode of attack. Examination of failed specimens is necessary to confirm that failure occurred by cracking rather than mechanical failure of reduced sections.
SCOPE
1.1 This practice covers procedures for preparing and conducting the polythionic acid test at room temperature, 22 °C to 25 °C (72 °F to 77 °F), to determine the relative susceptibility of stainless steels or other related materials (nickel-chromium-iron alloys) to intergranular stress corrosion cracking.
1.2 This practice can be used to evaluate stainless steels or other materials in the “as received” condition or after being subjected to high-temperature service, 482 °C to 815 °C (900 °F to 1500 °F), for prolonged periods of time.
1.3 This practice can be applied to wrought products, castings, and weld metal of stainless steels or other related materials to be used in environments containing sulfur or sulfides. Other materials capable of being sensitized can also be tested in accordance with this test.
1.4 This practice may be used with a variety of stress corrosion test specimens, surface finishes, and methods of applying stress.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For more specific precautionary statements, see Section 7.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard3 pagesEnglish language
- Standard3 pagesEnglish language
SIGNIFICANCE AND USE
3.1 Electrochemical corrosion rate measurements often provide results in terms of electrical current. Although the conversion of these current values into mass loss rates or penetration rates is based on Faraday’s Law, the calculations can be complicated for alloys and metals with elements having multiple valence values. This practice is intended to provide guidance in calculating mass loss and penetration rates for such alloys. Some typical values of equivalent weights for a variety of metals and alloys are provided.
3.2 Electrochemical corrosion rate measurements may provide results in terms of electrical resistance. The conversion of these results to either mass loss or penetration rates requires additional electrochemical information. Some approaches for estimating this information are given.
3.3 Use of this practice will aid in producing more consistent corrosion rate data from electrochemical results. This will make results from different studies more comparable and minimize calculation errors that may occur in transforming electrochemical results to corrosion rate values.
SCOPE
1.1 This practice covers the providing of guidance in converting the results of electrochemical measurements to rates of uniform corrosion. Calculation methods for converting corrosion current density values to either mass loss rates or average penetration rates are given for most engineering alloys. In addition, some guidelines for converting polarization resistance values to corrosion rates are provided.
1.2 The values stated in SI units are to be regarded as standard. Other units of measurement are included in this standard because of their usage.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method describes an EPR test method for quantitatively determining the relative degree of sensitization in AISI Type 304 and 304L stainless steels. The EPR test has found wide use as a means to provide a numerical level of sensitization in studies of the effects of sensitization on intergranular corrosion and intergranular stress corrosion cracking behavior. The results of this test method correlate with other test methods (for example, Practices A262 and Test Methods G28) that are commonly used to assess sensitization in stainless steels.
5.2 The EPR test can also be used for product acceptance, service evaluation, regulatory statutes, and manufacturing controls providing that both the supplier and user have agreed upon appropriate acceptance criteria and a sensitizing treatment. The test is not intended for design purposes since the test conditions accelerate corrosion in a manner that does not simulate any actual service environment.
5.3 The EPR test involves the measurement of the amount of charge resulting from the corrosion of the chromium-depleted regions surrounding the precipitated chromium carbide particles. Most of these particles in a sensitized microstructure are located at the grain boundaries. However, discrete particles located within grains (referred to as intragranular precipitates) will also contribute to the total measured charge. (See Fig. 2.) Therefore, it is important to examine the alloy microstructure following an EPR test to determine the relative proportion of corrosion sites associated with intergranular versus intragranular precipitates. Sites of intergranular attack will appear similar to grain boundary ditching as defined in Practice A of Practices A262.
FIG. 2 Schematic Microstructures After EPR Testing for Method A—Single Loop
Note 1: The calculation of Pa is based on the assumptions illustrated at left. Mild cases of sensitization usually result in a combination of intergranular attack and pitting as illustr...
SCOPE
1.1 These test methods cover a laboratory procedure for conducting an electrochemical reactivation (EPR) test on AISI Type 304 and 304L (UNS No. S30400 and S30403, respectively) stainless steels. These test methods can provide a nondestructive means of quantifying the degree of sensitization in Type 304 stainless steels (1, 2, 3).2 These EPR test methods have found wide acceptance in studies of the effects of sensitization on intergranular corrosion and intergranular stress corrosion cracking behavior (see Terminology G193). The EPR technique has been successfully used to evaluate other stainless steels and nickel base alloys (4), but the test conditions and evaluation criteria used were modified in each case from those cited in the current test methods. This standard test covers two tests, (1) Test Method A or Single Loop, and (2) Test Method B or Double Loop.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard12 pagesEnglish language
- Standard12 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This practice is normally used for stress-corrosion screening for the development of Al-Zn-Mg-Cu alloys containing less than 0.26 % copper. Effects on stress-corrosion resistance due to variables such as composition, thermo-mechanical processing, other fabrication variables, and magnitude of applied stress may be compared.
4.2 For a given mechanical method of stressing, the relative stress-corrosion resistance of the low copper Al-Zn-Mg-Cu alloys in atmospheric exposure correlates better with performance in boiling 6 % sodium chloride solution than with other accelerated testing media (7-9). In addition, this practice is relatively rapid.
4.3 This practice is not applicable to 2XXX (Al-Cu), 5XXX (Al-Mg), 6XXX (Al-Mg-Si), and the 7XXX (Al-Zn-Mg-Cu) series alloys containing more than 1.2 % copper.
4.3.1 For 7XXX series alloys containing between 0.26 % and 1.2 % copper, there is no general agreement as to whether this practice or Practice G44 correlates better with stress-corrosion resistance in service (5-8, 10).
SCOPE
1.1 This practice primarily covers the test medium which may be used with a variety of test specimens and methods of applying stress. Exposure times, criteria of failure, and so on, are variable and not specified.
1.2 This stress-corrosion testing practice is intended for statically loaded smooth non-welded or welded specimens of 7XXX series Al-Zn-Mg-Cu alloys containing less than 0.26 % copper.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Section 8 for additional precautions.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
4.1 The 3.5 % NaCl solution alternate immersion test provides a test environment for detecting materials that would be likely to be susceptible to SCC in natural outdoor environments, especially environments with marine influences.3,4,5 For determining actual serviceability of a material, other stress-corrosion tests should be performed in the intended service environment under conditions relating to the end use, including protective measures.
4.2 Although this test method is intended for certain alloy types and for testing products primarily in the short-transverse stressing direction, this method is useful for some other types of alloys and stressing directions.
SCOPE
1.1 This test method covers a uniform procedure for characterizing the resistance to stress-corrosion cracking (SCC) of high-strength aluminum alloy wrought products for the guidance of those who perform stress-corrosion tests, for those who prepare stress-corrosion specifications, and for materials engineers.
1.2 This test method covers method of sampling, type of specimen, specimen preparation, test environment, and method of exposure for determining the susceptibility to SCC of 2XXX (with 1.8 % to 7.0 % copper) and 7XXX (with 0.4 % to 2.8 % copper) aluminum alloy products, particularly when stressed in the short-transverse direction relative to the grain structure.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This practice is especially useful for evaluating the adequacy of quenching when performed on material in the as-quenched condition. The practice may also be used to study the effect of subsequent thermal processes (for example, paint or bonding cures) or of actual precipitation treatments on the inherent type of corrosion. Intergranular corrosion resistance of heat treatable aluminum alloys is often directly related to the quenching conditions applied after solution heat treatment and to the subsequent aging treatment.4
4.2 This practice is not well suited for non-heat treatable work hardening aluminum alloys, such as the 1XXX, 3XXX, and 5XXX series (see Test Method G67).
4.3 This practice does not deal with the interpretation of resulting intergranular corrosion. The significance of the extent and depth of any intergranular corrosion resulting from this test is to be agreed upon between producer and user.
SCOPE
1.1 This practice covers the procedures for immersion tests in sodium chloride + hydrogen peroxide solution. It is primarily for tests of wrought heat treatable aluminum alloys (2XXX and 7XXX) but may be used for other aluminum alloys, including castings. It sets forth the specimen preparation procedures and the environmental conditions of the test and the means for controlling them.
1.2 This practice is intended for evaluations during alloy development and for evaluating production where it may serve as a control test on the quality of successive lots of the same material (see MIL-H-6088 and U.S. Federal Test Method Std. 151b). Therefore strict test conditions are stipulated for maximum assurance that variations in results are attributable to lot-to-lot differences in the material being tested.
Note 1: This practice does not address sampling or interpretation or significance of results.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard3 pagesEnglish language
SIGNIFICANCE AND USE
4.1 Although there are ASTM test methods for exfoliation testing, they concentrate on specific procedures for test methodology itself. Existent test methods do not discuss material variables that can affect performance. Likewise they do not address the need to establish the suitability of an accelerated test for alloys never previously tested nor the need to correlate results of accelerated tests with tests in outdoor atmospheres and with end-use performance.
4.2 This guide is a compilation of the experience of investigators skilled in the art of conducting exfoliation tests and assessing the degree and significance of the damage encountered. The focus is on two general aspects: guides to techniques that will enhance the likelihood of obtaining reliable information, and tips and procedures to avoid pitfalls that could lead to erroneous results and conclusions.
4.3 The following three areas of testing are considered: the test materials starting with the “as-received” sample up through final specimen preparation, the corrosion test procedures including choice of test, inspection periods, termination point, and rating procedures, and analyses of results and methods for reporting them.
4.4 This guide is not intended as a specific corrosion test procedure by which to evaluate the resistance to exfoliation of an aluminum alloy product.
4.5 This guide is not intended as a basis for specifications, nor as a guide for material lot acceptance.
SCOPE
1.1 This guide differs from the usual ASTM standard in that it does not address a specific test. Rather, it is an introductory guide for new users of various standard exfoliation test methods with consideration for specific aluminum alloy families (see Terminology G193 for definition of exfoliation).
1.2 This guide covers aspects of specimen preparation, exposure, inspection, and evaluation for conducting exfoliation tests on aluminum alloys in both laboratory accelerated environments and in natural, outdoor atmospheres. The intent is to clarify any gaps in existent test methods.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide8 pagesEnglish language
- Guide8 pagesEnglish language
SIGNIFICANCE AND USE
3.1 The boiling ferric sulfate-sulfuric acid test may be applied to the following alloys in the wrought condition:
Alloy
Testing Time, h
N06007
120
N06022
24
N06030
120
N06059
24
N06200
24
N06455
24
N06600
24
N06625
120
N06686
24
N06985
120
N08020
120
N08367
24
Alloy
Testing Time, h
N08800
120
N08825A
120
N10276
24(A) While the ferric sulfate-sulfuric acid test does detect susceptibility to inter- granular corrosion in Alloy N08825, the boiling 65 % nitric acid test, Practices A262, Practice C, for detecting susceptibility to intergranular corrosion in stainless steels is more sensitive and should be used if the intended service is nitric acid.
3.2 This test method may be used to evaluate as-received material and to evaluate the effects of subsequent heat treatments. In the case of nickel-rich, chromium-bearing alloys, the test method may be applied to wrought and weldments of products. The test method is not applicable to cast products.
SCOPE
1.1 These test methods cover two tests as follows:
1.1.1 Method A, Ferric Sulfate-Sulfuric Acid Test (Sections 3 – 10, inclusive)—This test method describes the procedure for conducting the boiling ferric sulfate—50 % sulfuric acid test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to intergranular corrosion (see Terminology G193), which may be encountered in certain service environments. The uniform corrosion rate obtained by this test method, which is a function of minor variations in alloy composition, may easily mask the intergranular corrosion components of the overall corrosion rate on alloys N10276, N06022, N06059, and N06455.
1.1.2 Method B, Mixed Acid-Oxidizing Salt Test (Sections 11 – 18, inclusive)—This test method describes the procedure for conducting a boiling 23 % sulfuric + 1.2 % hydrochloric + 1 % ferric chloride + 1 % cupric chloride test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to display a step function increase in corrosion rate when there are high levels of grain boundary precipitation.
1.2 The purpose of these two test methods is to detect susceptibility to intergranular corrosion as influenced by variations in processing or composition, or both. Materials shown to be susceptible may or may not be intergranularly corroded in other environments. This must be established independently by specific tests or by service experience.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 Exception—Some desired corrosion rate units in 8.1.1 are given in inch-pound units.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Warning statements are given in 5.1.1, 5.1.3, 5.1.9, 13.1.1, and 13.1.11.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method provides a reliable prediction of the resistance or susceptibility, or both, to loss of material strength and ductility as a result of exposure to hydrogen-containing gaseous environments. This test method is applicable over a broad range of pressures, temperatures, and gaseous environments. The results from this test method can be used to evaluate the effects of material composition, processing, and heat treatment as well as the effects of changes in environment composition, temperature, and pressure. These results may or may not correlate with service experience for particular applications. Furthermore, this test method may not be suitable for the evaluation of high temperature hydrogen attack in steels unless suitable exposure time at the test conditions has taken place prior to the initiation of tensile testing to allow for the development of internal blistering, decarburization or cracking, or both.
SCOPE
1.1 This test method covers a procedure for determination of tensile properties of metals in high pressure or high temperature, or both, gaseous hydrogen-containing environments. It includes accommodations for the testing of either smooth or notched specimens.
1.2 This test method applies to all materials and product forms including, but not restricted to, wrought and cast materials.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test is a guide for evaluating magnesium anodes. The degree of correlation between this test and service performance has not been fully determined.
5.2 Test specimens from the same casting may not be identical because of inhomogeneities in the casting. A method of ensuring that identical test specimens are being evaluated is to retest a test specimen. The surface of the test specimen should be smoothed by machining before retesting. The new diameter should be measured and the test current adjusted so that the retest current density is 0.039 mA/cm2 (0.25 mA/in.2).
5.3 The values of potential and Ah per unit mass consumed as measured by this test method, may not agree with those found in field applications. It is unlikely that field results of Ah per unit mass consumed would ever be greater than those measured in this test. However, actual test comparisons are not sufficient to allow precise correlation of laboratory and field results.
SCOPE
1.1 This test method covers a laboratory procedure that measures the two fundamental performance properties of magnesium sacrificial anode test specimens operating in a saturated calcium sulfate, saturated magnesium hydroxide environment. The two fundamental properties are electrode (oxidation) potential and ampere hours (Ah) obtained per unit mass of specimen consumed. Magnesium anodes installed underground are usually surrounded by a backfill material that typically consists of 75 % gypsum (CaSO4·2H2O), 20 % bentonite clay, and 5 % sodium sulfate (Na2SO4). The calcium sulfate, magnesium hydroxide test electrolyte simulates the long term environment around an anode installed in the gypsum-bentonite-sodium sulfate backfill.
1.2 This test method is intended to be used for quality assurance by anode manufacturers or anode users. However, long term field performance properties may not be identical to property measurements obtained using this laboratory test.
Note 1: Refer to Terminology G193 for terms used in this test method.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautions, See Section 8 and Paragraph 9.1.1.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard5 pagesEnglish language
SIGNIFICANCE AND USE
5.1 This test method is designed to compare alloys and may be used as one method of screening materials prior to service. In general, this test method is more useful for stainless steels than the boiling magnesium chloride test of Practice G36. The boiling magnesium chloride test cracks materials with the nickel levels found in relatively resistant austenitic and duplex stainless steels, thus making comparisons and evaluations for many service environments difficult.
5.2 This test method is intended to simulate cracking in water, especially cooling waters that contain chloride. It is not intended to simulate cracking that occurs at high temperatures (greater than 200 °C or 390 °F) with chloride or hydroxide.
Note 1: The degree of cracking resistance found in full-immersion tests may not be indicative of that for some service conditions comprising exposure to the water-line or in the vapor phase where chlorides may concentrate.
5.3 Correlation with service experience should be obtained when possible. Different chloride environments may rank materials in a different order.
5.4 In interlaboratory testing, this test method cracked annealed UNS S30400 and S31600 but not more resistant materials, such as annealed duplex stainless steels or higher nickel alloys, for example, UNS N08020 (for example 20Cb-33 stainless). These more resistant materials are expected to crack when exposed to Practice G36 as U-bends. Materials which withstand this sodium chloride test for a longer period than UNS S30400 or S31600 may be candidates for more severe service applications.
5.5 The repeatability and reproducibility data from Section 12 and Appendix X1 must be considered prior to use. Interlaboratory variation in results may be expected as occurs with many corrosion tests. Acceptance criteria are not part of this test method and if needed are to be negotiated by the user and the producer.
SCOPE
1.1 This test method covers a procedure for conducting stress-corrosion cracking tests in an acidified boiling sodium chloride solution. This test method is performed in 25 % (by mass) sodium chloride acidified to pH 1.5 with phosphoric acid. This test method is concerned primarily with the test solution and glassware, although a specific style of U-bend test specimen is suggested.
1.2 This test method is designed to provide better correlation with chemical process industry experience for stainless steels than the more severe boiling magnesium chloride test of Practice G36. Some stainless steels which have provided satisfactory service in many environments readily crack in Practice G36, but have not cracked during interlaboratory testing (see Section 12) using this sodium chloride test method.
1.3 This boiling sodium chloride test method was used in an interlaboratory test program to evaluate wrought stainless steels, including duplex (ferrite-austenite) stainless and an alloy with up to about 33 % nickel. It may also be employed to evaluate these types of materials in the cast or welded conditions.
1.4 This test method detects major effects of composition, heat treatment, microstructure, and stress on the susceptibility of materials to chloride stress-corrosion cracking. Small differences between samples such as heat-to-heat variations of the same grade are not likely to be detected.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8.
1.7 This international standard was developed in accordance with internationally recogni...
- Standard10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 These test methods describe laboratory tests to determine the presence of mu-phase in Wrought Nickel-Rich, Chromium, and Molybdenum-Bearing Alloys through comparison of microstructure observed for etched metallographic specimens to a glossary of photomicrographs displaying the presence and absence of mu-phase in the microstructure. The presence of mu-phase in the microstructure may significantly reduce the corrosion resistance, strength, toughness and ductility of Wrought Nickel-Rich, Chromium, and Molybdenum-Bearing Alloys.
SCOPE
1.1 This practice incorporates etching and metallographic examination of Wrought Nickel-Rich, Chromium, Molybdenum-Bearing Alloys such as, but not limited to, UNS N06686 and UNS N10276.
1.2 Microstructures have a strong influence on properties and successful application of metals and alloys. The presence of mu-phase in the microstructure may significantly reduce the corrosion resistance of Wrought Nickel-Rich, Chromium, and Molybdenum-Bearing Alloys.
1.3 This practice may be used to determine the presence of mu-phase in Wrought Nickel-Rich, Chromium, and Molybdenum-Bearing Alloys through comparison of microstructure observed for etched metallographic specimens to a glossary of photomicrographs displaying the presence and absence of mu-phase in the microstructure.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This test method is suitable for in-service evaluation and for use in research and development work.
4.2 This test method is applicable to members regardless of their size or the depth of concrete cover over the reinforcing steel. Concrete cover in excess of 75 mm (3 in.) can result in an averaging of adjacent reinforcement corrosion potentials that can result in a loss of the ability to discriminate variation in relative corrosion activity.
4.3 This test method is not applicable to reinforced concrete structures with epoxy-coated reinforcement.
4.4 This test method is not applicable to reinforced concrete structures in which waterproofing membranes are located between the reinforcement cage and the concrete surface as they can prevent the conduction of electricity and result in erroneous readings.
4.5 This test method may be used at any time during the life of a concrete member after the concrete has set, although it is generally most useful for evaluating mature reinforced concrete that is suspected to be susceptible to corrosion.
4.6 The results obtained by the use of this test method shall not be considered as a means for estimating the structural properties of the steel or of the reinforced concrete member.
4.7 Temperature and humidity can impact potential readings. This is particularly important for periodic testing of the same test location. An increase in the temperature leads to increasing ionic mobility, which in turn affects the reference electrode’s potential. The temperature influence can be neglected if the measurements are taken within the range of 22.2 °C ± 5.5 °C (72 °F ± 10 °F). Otherwise, the temperature-dependency of the measurements must be taken into account.
4.8 The potential measurements should be interpreted by engineers or technical specialists experienced in the fields of concrete materials and corrosion testing. It is often necessary to use other complementary data such as chloride contents, depth of carbonation, ...
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1.1 This test method covers the estimation of the electrical corrosion potential of uncoated reinforcing steel in field and laboratory concrete, for the purpose of determining the corrosion activity of the reinforcing steel.
1.2 This test method is limited by electrical circuitry. Concrete surface in building interiors and desert environments lose sufficient moisture so that the concrete resistivity becomes so high that special testing techniques not covered in this test method may be required (see 5.1.4.1). Concrete surfaces that are coated or treated with sealers may not provide an acceptable electrical circuit. The basic configuration of the electrical circuit is shown in Fig. 1.
FIG. 1 Reference Electrode Circuitry
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The test method was developed for use with high strength aluminum alloys (2XXX and Cu containing 7XXX) that are normally tested in 3.5 weight % NaCl by alternate immersion. However, the concept which uses residual strength as a measure of damage evolution (in this case environmentally assisted cracking) can, in principle, be applied to any alloy and environmental system.
5.2 This test method has been developed for research studies of alloys and tempers with improved resistance to SCC. The test results permit different material variants to be compared with a high degree of confidence and with much more precision than the results of pass/fail tests. Thus, it is particularly useful for comparing materials with similar levels of resistance to stress-corrosion cracking. The procedure could be modified for use as a quality assurance tool but this has not been a primary purpose during its development.
5.3 The exposure periods and conditions that are described in this test method apply specifically to high strength aluminum alloys, but the statistical techniques should be valid for other alloy systems with different exposure conditions.
5.4 Although this particular procedure was primarily intended for testing products in the short-transverse stressing direction, it is useful for other stressing directions, particularly the long-transverse direction in sheet and thin plate products.
5.5 Determination of the actual serviceability of a material requires stress-corrosion testing performed in the intended service environment, under conditions relating to the end use, including protective measures such as coatings and inhibitors and is outside the scope of this test method.
5.5.1 There is no good way to compare test environments to actual service because most service environments have large inherent variability with respect to a single structure that may experience many different environments or with respect to two identical structures that serve in different l...
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1.1 This test method covers procedures for evaluation of stress corrosion cracking (SCC) resistance by the breaking load test method, a concept which uses residual strength as the measure of damage evolution (in this case environmentally assisted cracking).
1.2 This test method covers specimen type and replication, test environment, stress levels, exposure periods, final strength determination, and statistical analysis of the raw residual strength data.
1.3 The test method was developed for use with heat-treatable aluminum alloys, that is, 2XXX alloys and 7XXX with 1.2 to 3.0 % Cu, and test specimens oriented in the short-transverse direction relative to grain structure (1, 2).2 However, the residual strength measurements and the statistics used to analyze the data are not specific to heat-treatable aluminum alloys and can be used for other specimen orientations and different types of materials.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 Guide G96 describes a linear-polarization method and an electrical resistance method for online monitoring of corrosion in plant equipment without the need to enter the system physically to withdraw coupons. These two online monitoring techniques are useful in systems in which process upsets or other problems can create corrosive conditions. An early warning of corrosive attack can permit remedial action before significant damage occurs to process equipment. The two methods described in Guide G96 are suitable for uniform corrosion, but may not be sensitive enough for non-uniform corrosion, especially localized corrosion. This guide describes a new method for monitoring non-uniform corrosion, especially localized corrosion.
4.2 The CMAS technique measures the net anodic current or net cathodic current from each of the individual electrodes (Iaex or Icex in Fig. 1), which is the characteristic of non-uniform corrosion such as localized corrosion and uneven general corrosion. Therefore, the CMAS technique can be used to estimate the rate of uneven general corrosion and localized corrosion (see Section 5).
FIG. 1 Principle of CMAS Probe
Note 1: The upper section shows the electron flows from the corroding area to the less corroding areas inside a metal when localized corrosion takes place; the lower section shows the electron flows after the anodic and cathodic areas are separated into individual small electrodes and coupled through an external circuit that measures the anodic current (Iaex) and cathodic current (Icex) through each of the individual electrodes (4).
4.3 Unlike uniform corrosion, the rate of non-uniform corrosion, especially localized corrosion, can vary significantly from one area to another area of the same metal exposed to the same environment. Allowance shall be made for such variations when the measured non-uniform corrosion rate is used to estimate the penetration of the actual metal structure or the actual wall of process equipment. T...
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1.1 This guide outlines the procedure for conducting corrosion monitoring in laboratories and plants by use of the coupled multielectrode array sensor (CMAS) technique.
1.2 For plant applications, this technique can be used to assess the instantaneous non-uniform corrosion rate, including localized corrosion rate, on a continuous basis, without removal of the monitoring probes, from the plant.
1.3 For laboratory applications, this technique can be used to study the effects of various testing conditions and inhibitors on non-uniform corrosion, including pitting corrosion and crevice corrosion.
1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide11 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The U-bend specimen may be used for any metal alloy sufficiently ductile to be formed into the U-shape without mechanically cracking. The specimen is most easily made from strip or sheet but can be machined from plate, bar, castings, or weldments; wire specimens may be used also.
5.2 Since the U-bend usually contains large amounts of elastic and plastic strain, it provides one of the most severe tests available for smooth (as opposed to notched or precracked) stress-corrosion test specimens. The stress conditions are not usually known and a wide range of stresses exist in a single stressed specimen. The specimen is therefore unsuitable for studying the effects of different applied stresses on stress-corrosion cracking or for studying variables that have only a minor effect on cracking. The advantage of the U-bend specimen is that it is simple and economical to make and use. It is most useful for detecting large differences between the stress-corrosion cracking resistance of (a) different metals in the same environment, (b) one metal in different metallurgical conditions in the same environment, or (c) one metal in several environments.
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1.1 This practice covers procedures for making and using U-bend specimens for the evaluation of stress-corrosion cracking in metals. The U-bend specimen is generally a rectangular strip that is bent 180° around a predetermined radius and maintained in this constant strain condition during the stress-corrosion test. Bends slightly less than or greater than 180° are sometimes used. Typical U-bend configurations showing several different methods of maintaining the applied stress are shown in Fig. 1.
FIG. 1 Typical Stressed U-bends
1.2 U-bend specimens usually contain both elastic and plastic strain. In some cases (for example, very thin sheet or small diameter wire) it is possible to form a U-bend and produce only elastic strain. However, bent-beam (Practice G39 or direct tension (Practice G49)) specimens are normally used to study stress-corrosion cracking of strip or sheet under elastic strain only.
1.3 This practice is concerned only with the test specimen and not the environmental aspects of stress-corrosion testing, which are discussed elsewhere (1)2 and in Practices G35, G36, G37, G41, G44, G103 and Test Method G123.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
5.1 Autoclave tests are commonly used to evaluate the corrosion performance of metallic and non-metallic materials under simulated HP and HTHP service conditions. Examples of service environments in which HP and HTHP corrosion tests have been used include chemical processing, petroleum production and refining, food processing, pressurized cooling water, electric power systems, and aerospace propulsion.
5.2 For the applications of corrosion testing listed in 5.1, the service environment involves handling corrosive and potentially hazardous media under conditions of high pressure or high temperature, or both. The temperature and pressure, among other parameters, usually drive the composition and properties of the aqueous phase and, hence, the severity of the corrosion process. Consequently, the laboratory evaluation of corrosion severity cannot be performed in conventional low pressure glassware without making potentially invalid assumptions as to the potential effects of high temperature and pressure on corrosion severity.
5.3 Therefore, there is a substantial need to provide standardized methods by which corrosion testing can be performed under HP and HTHP. In many cases, however, the standards used for exposure of specimens in conventional low-pressure glassware experiments cannot be followed due to the limitations of access, volume, and visibility arising from the construction of high-pressure test cells. This guide refers to existing corrosion standards and practices, as applicable, and then goes further in areas in which specific guidelines for performing HP and HTHP corrosion testing are needed.
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1.1 This guide covers procedures, specimens, and equipment for conducting laboratory corrosion tests on metallic materials under conditions of high pressure (HP) or the combination of high temperature and high pressure (HTHP). See 3.2 for definitions of high pressure and temperature.
1.2 The procedures and methods in this guide are applicable for conducting mass loss corrosion, localized corrosion, and electrochemical tests as well as for use in environmentally induced cracking tests that need to be conducted under HP or HTHP conditions.
1.3 The primary purpose for this guide is to promote consistency of corrosion test results. Furthermore, this guide will aid in the comparison of corrosion data between laboratories or testing organizations that utilize different equipment.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide8 pagesEnglish language
- Guide8 pagesEnglish language
SIGNIFICANCE AND USE
6.1 Leak detector solutions may cause stress-corrosion cracking of different alloys. If a leak detector solution is found to cause stress-corrosion cracking in accordance with Test Method G186, it should not be used on brasses or other copper alloys. If a leak detector solution is found not to cause stress-corrosion cracking in accordance with Test Method G186, it may cause stress-corrosion cracking of copper or other alloys under unspecified conditions.
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1.1 This specification covers the requirements for leak detector solutions suitable for use in checking the leakage of valves, pipes, fittings, joints, and so forth of a pressurized gas system fabricated from brasses and other copper alloys.
1.2 This specification deals with the stress-corrosion cracking aspect of leak detector solutions. The effectiveness, chemical, physical and mechanical properties of leak detector solutions are not within the scope of this specification.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and to determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Technical specification2 pagesEnglish language
SIGNIFICANCE AND USE
3.1 In this test method, susceptibility to localized corrosion of aluminum is indicated by a protection potential (Eprot) determined by cyclic galvanostaircase polarization (1). The more noble this potential, the less susceptible is the alloy to initiation of localized corrosion. The results of this test method are not intended to correlate in a quantitative manner with the rate of propagation of localized corrosion that one might observe in service.
3.2 The breakdown (Eb), and protection potentials (Eprot) determined by the cyclic GSCP method correlate with the constant potential corrosion test (immersion-glassware) result for aluminum (1, 6, 7). When the applied potential was more negative than the GSCP Eprot, no pit initiation was observed. When the applied potential was more positive than the GSCP Eprot, pitting occurred even when the applied potential was less negative than Eb.
3.2.1 Severe crevice corrosion occurred when the separation of Eb and Eprot was 500 mV or greater and Eprot was less than −400 mV Vs. SCE (in 100 ppm NaCl) (1, 6, 8). For aluminum, Eprot determined by cyclic GSCP agrees with the repassivation potential determined by the scratch potentiostatic method (1, 9). Both the scratch potentiostatic method and the constant potential technique for determination of Eprot require much longer test times and are more involved techniques than the GSCP method.
3.3 DeBerry and Viebeck (3-5) found that the breakdown potentials (Eb) (galvanodynamic polarization, similar to GSCP but no kinetic information) had a good correlation with the inhibition of localized corrosion of 304L stainless steel by surface active compounds. They attained accuracy and precision by avoiding the strong induction effect which they observed by the potentiodynamic technique.
3.4 If this test method is followed using the specific alloy discussed it will provide (GSCP) measurements that will reproduce data developed at other times in other laboratories.
3.5 Eb and Eprot...
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1.1 This test method covers a procedure for conducting cyclic galvanostaircase polarization (GSCP) to determine relative susceptibility to localized corrosion (pitting and crevice corrosion) for aluminum alloy 3003-H14 (UNS A93003) (1).2 It may serve as guide for examination of other alloys (2-5). This test method also describes a procedure that can be used as a check for one's experimental technique and instrumentation.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
4.1 It is important to be able to determine the extent of pitting, either in a service application in which it is necessary to predict the remaining life in a metal structure, or in laboratory test programs that are used to select the most pitting-resistant materials for service. The purpose of the study is crucial in determining the appropriate examination and evaluation steps.
4.2 Some typical purposes of laboratory tests include, but are not limited to, evaluating performance of alloys, determining whether an alloy is resistant to the environment, evaluating how environmental conditions including corrosion inhibitor affect or prevent pitting, and evaluating whether a lot of metal is sufficiently resistant for its use in a particular application or environment.
4.3 Some typical purposes of field studies include, but are not limited to, determining if pits are likely to grow and cause leak or release of process fluid, and assisting a determination of whether to replace or repair damage from pits (remaining life assessment).
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1.1 This guide covers the selection of procedures that can be used in the examination and evaluation of pitted metals. These procedures include both nondestructive and destructive approaches.
1.2 The procedures covered in this guide include those that may be used in laboratory evaluations of corroded metal specimens and field examinations and inspections.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3.1 Exception—In X1.2.1, mils per year (MPY) are regarded as standard for the target corrosion rate.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide13 pagesEnglish language
- Guide13 pagesEnglish language
SIGNIFICANCE AND USE
4.1 The C-ring is a versatile, economical specimen for quantitatively determining the susceptibility to stress-corrosion cracking of all types of alloys in a wide variety of product forms. It is particularly suitable for making transverse tests of tubing and rod and for making short-transverse tests of various products as illustrated for plate in Fig. 1.
FIG. 1 Sampling Procedure for Testing Various Products
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1.1 This practice covers the essential features of the design and machining, and procedures for stressing, exposing, and inspecting C-ring type of stress-corrosion test specimens. An analysis is given of the state and distribution of stress in the C-ring.
1.2 Specific considerations relating to the sampling process and to the selection of appropriate test environments are outside the scope of this practice.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
3.1 The availability of a standard procedure, standard material, and a standard plot should make it easy for an investigator to check his techniques. This should lead to polarization curves in the literature which can be compared with confidence.
3.2 Samples of a standard ferritic Type 430 stainless steel (UNS S43000) used in obtaining standard reference plot are available for those who wish to check their own test procedure and equipment.3
3.3 Standard potentiodynamic polarization plots are shown for a lot of material originally purchased in 1992. This reference test method is not applicable for standard material purchased before 1992. These reference data are based on the results from different laboratories that followed the standard procedure, using that material in 1.0 N H2SO4. The four sigma probability bands for current density values are shown at each potential to indicate the acceptable range of values.
3.4 This reference test method may not be appropriate for polarization testing of all materials or in all environments.
3.5 This reference test method is intended for use in evaluating the accuracy of a given electrochemical test apparatus, not for use in evaluating materials performance. Therefore, the use of the plots in Fig. 1 is not recommended to evaluate alloys other than Type 430, or lots of Type 430 other than those available through Metal Samples. The use of the data in this reference test method in this manner is beyond the scope and intended use of this reference test method. Users of this reference test method are advised to evaluate test results relative to the scatter bands corresponding to the particular lot of Type 430 stainless steel that was tested.
FIG. 1 Typical Standard Potentiodynamic Anodic Polarization Plot
CURRENT DENSITY (μA/cm2)
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1.1 This reference test method covers an experimental procedure for checking experimental technique and instrumentation. If followed, this reference test method will provide repeatable potentiodynamic anodic polarization measurements that will reproduce data determined by others at other times and in other laboratories provided all laboratories are testing reference samples from the same lot of Type 430 stainless steel.
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard9 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This classification involves alphabetical ratings intended only to provide a qualitative guide for materials selection. The ratings are based primarily on the results of standard corrosion tests.
4.2 Interpretations of the SCC ratings in terms of typical problem areas including service experience are given in Table 1. Practical experience has shown that SCC problems with aluminum alloys generally have involved situations where the direction and magnitude of the tensile stresses resulting from manufacturing or use, or both, of the material were not recognized. (A) The sum of all stresses including those from service loads (applied), heat treatment, straightening, forming, and so forth.
4.3 A list of the SCC ratings for the heat-treatable aluminum alloy products is given in Table 2. Revisions to the table will be required as new materials become available and additional test results are accumulated. (A) The ratings apply to standard mill products in the types of tempers indicated, including stress-relieved tempers, and could be invalidated in some cases by application of nonstandard thermal treatments or mechanical deformation at room temperature by the user.(B) Test direction refers to orientation of the stressing direction relative to the directional grain structure typical of wrought materials, which in the case of extrusions and forgings may not be predictable from the geometrical cross section of the product.
L — Longitudinal: parallel to direction of principal metal extension during manufacture of the product.
LT—Long Transverse: perpendicular to direction of principal metal extension. In products whose grain structure clearly shows directionality (width-to-thickness ratio greater than two) it is that perpendicular direction parallel to the major grain dimension.
ST—Short Transverse: perpendicular to direction of principal metal extension and parallel to minor dimension of grains in products with significant grain directionality.(C) Sections wit...
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1.1 This classification covers alphabetical ratings of the relative resistance to SCC of various mill product forms of the wrought 2XXX, 6XXX, and 7XXX series heat-treated aluminum alloys and the procedure for determining the ratings.
1.2 The ratings do not apply to metal in which the metallurgical structure has been altered by welding, forming, or other fabrication processes.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The bent-beam specimen is designed for determining the stress-corrosion behavior of alloy sheets and plates in a variety of environments. The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. For testing in the plastic range, U-bend specimens should be employed (see Practice G30). Although it is possible to stress bent-beam specimens into the plastic range, the stress level cannot be calculated for plastically-stressed three- and four-point loaded specimens as well as the double-beam specimens. Therefore, the use of bent-beam specimens in the plastic range is not recommended for general use.
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1.1 This practice covers procedures for designing, preparing, and using bent-beam stress-corrosion specimens.
1.2 Different specimen configurations are given for use with different product forms, such as sheet or plate. This practice is applicable to specimens of any metal that are stressed to levels less than the elastic limit of the material, and therefore, the applied stress can be accurately calculated or measured (see Note 1). Stress calculations by this practice are not applicable to plastically stressed specimens.
Note 1: It is the nature of these practices that only the applied stress can be calculated. Since stress-corrosion cracking is a function of the total stress, for critical applications and proper interpretation of results, the residual stress (before applying external stress) or the total elastic stress (after applying external stress) should be determined by appropriate nondestructive methods, such as X-ray diffraction (1).2
1.3 Test procedures are given for stress-corrosion testing by exposure to gaseous and liquid environments.
1.4 The bent-beam test is best suited for flat product forms, such as sheet, strip, and plate. For plate material the bent-beam specimen is more difficult to use because more rugged specimen holders must be built to accommodate the specimens. A double-beam modification of a four-point loaded specimen to utilize heavier materials is described in 10.5.
1.5 The exposure of specimens in a corrosive environment is treated only briefly since other practices deal with this aspect, for example, Practices D1141, G30, G36, G44, G50, and G85. The experimenter is referred to ASTM Special Technical Publication 425 (2).
1.6 The bent-beam practice generally constitutes a constant strain (deflection) test. Once cracking has initiated, the state of stress at the tip of the crack as well as in uncracked areas has changed, and therefore, the known or calculated stress or strain values discussed in this practice apply only to the state of stress existing before initiation of cracks.
1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (For more specific safety hazard information see Section 7 and 12.1.)
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard8 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The slow strain rate test is used for relatively rapid screening or comparative evaluation, or both, of environmental, processing or metallurgical variables, or both, that can affect the resistance of a material to EAC. For example, this testing technique has been used to evaluate materials, heat treatments, chemical constituents in the environment, and temperature and chemical inhibitors.
5.2 Where possible, the application of the SSR test and data derived from its use should be used in combination with service experience or long-term EAC data, or both, obtained through literature sources or additional testing using other testing techniques. In applications where there has been little or no prior experience with SSR testing or little EAC data on the particular material/environment combination of interest, the following steps are recommended:
5.2.1 The SSR tests should be conducted over a range of applied extension rates (that is, usually at least one order of magnitude in applied extension rate above and below 10−6 in./s (2.54 × 10–5 mm/s) to determine the effect of strain rate or rate of increase of the stress or stress intensity factor on susceptibility to EAC.
5.2.2 Constant load or strain EAC tests should also be conducted in simulated service environments, and service experience should be obtained so that a correlation between SSR test results and anticipated service performance can be developed.
5.3 In many cases the SSR test has been found to be a conservative test for EAC. Therefore, it may produce failures in the laboratory under conditions which do not necessarily cause EAC under service application. Additionally, in some limited cases, EAC indications are not found in smooth tension SSR tests even when service failures have been observed. This effect usually occurs when there is a delay in the initiation of localized corrosion processes. Therefore, the suggestions given in 5.2 are strongly encouraged.
5.4 In some cases, EAC will only o...
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1.1 This practice covers procedures for the design, preparation, and use of axially loaded, tension test specimens and fatigue pre-cracked (fracture mechanics) specimens for use in slow strain rate (SSR) tests to investigate the resistance of metallic materials to environmentally assisted cracking (EAC). While some investigators utilize SSR test techniques in combination with cyclic or fatigue loading, no attempt has been made to incorporate such techniques into this practice.
1.2 Slow strain rate testing is applicable to the evaluation of a wide variety of metallic materials in test environments which simulate aqueous, nonaqueous, and gaseous service environments over a wide range of temperatures and pressures that may cause EAC of susceptible materials.
1.3 The primary use of this practice is to furnish accepted procedures for the accelerated testing of the resistance of metallic materials to EAC under various environmental conditions. In many cases, the initiation of EAC is accelerated through the application of a dynamic strain in the gauge section or at a notch tip or crack tip, or both, of a specimen. Due to the accelerated nature of this test, the results are not intended to necessarily represent service performance, but rather to provide a basis for screening, for detection of an environmental interaction with a material, and for comparative evaluation of the effects of metallurgical and environmental variables on sensitivity to known environmental cracking problems.
1.4 Further information on SSR test methods is available in ISO 7539 and in the references provided with this practice (1-6).2
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility ...
- Standard7 pagesEnglish language
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
4.1 This test environment is believed to give an accelerated ranking of the relative or absolute degree of stress-corrosion cracking susceptibility for different brasses. It has been found to correlate well with the corresponding service ranking in environments that cause stress-corrosion cracking which is thought to be due to the combined presence of traces of moisture and ammonia vapor. The extent to which the accelerated ranking correlates with the ranking obtained after long-term exposure to environments containing corrodents other than ammonia is not at present known. Examples of such environments may be severe marine atmospheres (Cl−), severe industrial atmospheres (predominantly SO2), and super-heated ammonia-free steam.
4.2 It is not possible at present to specify any particular time to failure (defined on the basis of any particular failure criteria) in pH 7.2 Mattsson’s solution that corresponds to a distinction between acceptable and unacceptable stress-corrosion behavior in brass alloys. Such particular correlations must be determined individually.
4.3 Mattsson's solution of pH 7.2 may also cause stress independent general and intergranular corrosion of brasses to some extent. This leads to the possibility of confusing stress-corrosion failures with mechanical failures induced by corrosion-reduced net cross sections. This danger is particularly great with small cross section specimens, high applied stress levels, long exposure periods and stress-corrosion resistant alloys. Careful metallographic examination is recommended for correct diagnosis of the cause of failure. Alternatively, unstressed control specimens may be exposed to evaluate the extent to which stress independent corrosion degrades mechanical properties.
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1.1 This practice covers the preparation and use of Mattsson’s solution of pH 7.2 as an accelerated stress-corrosion cracking test environment for brasses (copper-zinc base alloys). The variables (to the extent that these are known at present) that require control are described together with possible means for controlling and standardizing these variables.
1.2 This practice is recommended only for brasses (copper-zinc base alloys). The use of this test environment is not recommended for other copper alloys since the results may be erroneous, providing completely misleading rankings. This is particularly true of alloys containing aluminum or nickel as deliberate alloying additions.
1.3 This practice is intended primarily where the test objective is to determine the relative stress-corrosion cracking susceptibility of different brasses under the same or different stress conditions or to determine the absolute degree of stress corrosion cracking susceptibility, if any, of a particular brass or brass component under one or more specific stress conditions. Other legitimate test objectives for which this test solution may be used do, of course, exist. The tensile stresses present may be known or unknown, applied or residual. The practice may be applied to wrought brass products or components, brass castings, brass weldments, and so forth, and to all brasses. Strict environmental test conditions are stipulated for maximum assurance that apparent variations in stress-corrosion susceptibility are attributable to real variations in the material being tested or in the tensile stress level and not to environmental variations.
1.4 This practice relates solely to the preparation and control of the test environment. No attempt is made to recommend surface preparation or finish, or both, as this may vary with the test objectives. Similarly, no attempt is made to recommend particular stress-corrosion test specimen configurations or methods of applying the stress. Test specimen configurations that may be used are referenced in Practice G30 and STP 425.2
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included ...
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
5.1 Brass components are routinely used in compressed gas service for valves, pressure regulators, connectors and many other components. Although soft brass is not susceptible to ammonia SCC, work-hardened brass is susceptible if its hardness exceeds about 54 HR 30T (55HRB) (Rockwell scale). Normal assembly of brass components should not induce sufficient work hardening to cause susceptibility to ammonia SCC. However, it is has been observed that over-tightening of the components will render them susceptible to SCC, and the problem becomes more severe in older components that have been tightened many times. In this test, the specimens are obtained in the hardened condition and are strained beyond the elastic limit to accelerate the tendency towards SCC.
5.2 It is normal practice to use LDFs to check pressurized systems to assure that leaking is not occurring. LDFs are usually aqueous solutions containing surfactants that will form bubbles at the site of a leak. If the LDF contains ammonia or other agent that can cause SCC in brass, serious damage can occur to the system that will compromise its safety and integrity.
5.3 It is important to test LDFs to assure that they do not cause SCC of brass and to assure that the use of these products does not compromise the integrity of the pressure containing system.
5.4 It has been found that corrosion of brass is necessary before SCC can occur. The reason for this is that the corrosion process results in cupric and cuprous ions accumulating in the electrolyte. Therefore, adding copper metal and cuprous oxide (Cu2O) to the aqueous solution accelerates the SCC process if agents that cause SCC are present. However, adding these components to a solution that does not cause SCC will not make stressed brass crack.
5.5 Repeated application of the solution to the specimen followed by a drying period causes the components in the solution to concentrate thereby further increasing the rate of cracking. This also simulates se...
SCOPE
1.1 This test method covers an accelerated test method for evaluating the tendency of gas leak detection fluids (LDFs) to cause stress corrosion cracking (SCC) of brass components in compressed gas service.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard10 pagesEnglish language
SIGNIFICANCE AND USE
4.1 The 3.5 % NaCl alternate immersion procedure is a general, all-purpose procedure that produces valid comparisons for most metals, particularly when specimens are exposed at high levels of applied stress or stress intensity.
4.2 While the alternate immersion test is an accelerated test and is considered to be representative of certain natural conditions, it is not intended to predict performance in specialized chemical environments in which a different mode of cracking may be operative. For example, it does not predict the performance of aluminum alloys in highly acidic environments such as heated inhibited red fuming nitric acid (IRFNA). For such cases, the results of the alternate immersion test are of doubtful significance until a relationship has been established between it and anticipated service environments.
4.3 While this practice is applicable in some degree to all metals, it is not equally discriminative of all alloys, even within the same metal system. Consequently, information should be established to allow comparisons of performances of the alloy of interest in the alternate immersion test and in natural environments.
Note 2: The alternate immersion concept can be useful for exposure of corrosion specimens in other solutions because the procedure and apparatus provide a controlled set of conditions. Details of this are beyond the scope of this practice.
SCOPE
1.1 This practice covers procedures for making alternate immersion stress corrosion tests in 3.5 % sodium chloride (NaCl) (Note 1). It is primarily for tests of aluminum alloys (Test Method G47) and ferrous alloys, but may be used for other metals exhibiting susceptibility to chloride ions. It sets forth the environmental conditions of the test and the means for controlling them.
Note 1: Alternate immersion stress corrosion exposures are sometimes made in substitute ocean water (without heavy metals) prepared in accordance with Practice D1141. The general requirements of this present practice are also applicable to such exposures except that the reagents used, the solution concentration, and the solution pH should be as specified in Practice D1141.
1.2 This practice can be used for both stressed and unstressed corrosion specimens. Historically, it has been used for stress-corrosion cracking testing, but is often used for other forms of corrosion, such as uniform, pitting, intergranular, and galvanic.
1.3 This practice is intended for alloy development and for applications where the alternate immersion test is to serve as a control test on the quality of successive lots of the same material. Therefore, strict test conditions are stipulated for maximum assurance that variations in results are attributable to variations in the material being tested.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard4 pagesEnglish language
- Standard4 pagesEnglish language
SIGNIFICANCE AND USE
5.1 The corrosion observed on steel and other materials under thermal insulation is of great concern for many industries including chemical processing, petroleum refining and electric power generation. In most cases, insulation is utilized on piping and vessels to maintain the temperatures of the operating systems for process stabilization and energy conservation. However, these situations can also provide the prerequisites for the occurrence of general or localized corrosion, or both, and in stainless steels, stress corrosion cracking. For example, combined with elevated temperatures, CUI can sometimes result in aqueous corrosion rates for steel that are greater than those found in conventional immersion tests conducted in either open or closed systems (see Fig. 1).3 This figure shows actual CUI data determined in the field compared with the corrosion data from fully immersed corrosion coupons tests.
FIG. 1 Comparison of Actual Plant CUI Corrosion Rates Measurements (Open Data Points Shown is for Plant CUI) with Laboratory Corrosion Data Obtained in Open and Closed Systems
Note 1: The actual CUI corrosion rates can be in excess of the those obtain in conventional laboratory immersion exposures.
5.2 This guide provides a technical basis for laboratory simulation of many of the manifestations of CUI. This is an area where there has been a need for better simulation techniques, but until recently, has eluded many investigators. Much of the available experimental data is based on field and in-plant measurements of remaining wall thickness. Laboratory studies have generally been limited to simple immersion tests for the corrosivity of leachants from thermal insulation on corrosion coupons using techniques similar to those given in Guide G31. The field and inplant tests give an indication of corrosion after the fact and can not be easily utilized for experimental purposes. The use of coupons in laboratory immersion tests can give a general indication of corrosio...
SCOPE
1.1 This guide covers the simulation of corrosion under insulation (CUI), including both general and localized attack, on insulated specimens cut from pipe sections exposed to a corrosive environment usually at elevated temperature. It describes a CUI exposure apparatus (hereinafter referred to as a CUI-Cell), preparation of specimens, simulation procedures for isothermal or cyclic temperature, or both, and wet/dry conditions, which are parameters that need to be monitored during the simulation and the classification of simulation type.
1.2 The application of this guide is broad and can incorporate a range of materials, environments and conditions that are beyond the scope of a single test method. The apparatus and procedures contained herein are principally directed at establishing acceptable procedures for CUI simulation for the purposes of evaluating the corrosivity of CUI environments on carbon and low alloy pipe steels, and may possibly be applicable to other materials as well. However, the same or similar procedures can also be utilized for the evaluation of (1) CUI on other metals or alloys, (2) anti-corrosive treatments on metal surfaces, and (3) the potential contribution of thermal insulation and its constituents on CUI. The only requirements are that they can be machined, formed or incorporated into the CUI-Cell pipe configuration as described herein.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was ...
- Guide11 pagesEnglish language
SIGNIFICANCE AND USE
4.1 When two dissimilar metals in electrical contact are exposed to a common electrolyte, one of the metals can undergo increased corrosion while the other can show decreased corrosion. This type of accelerated corrosion is referred to as galvanic corrosion. Because galvanic corrosion can occur at a high rate, it is important that a means be available to alert the user of products or equipment that involve the use of dissimilar metal combinations in an electrolyte of the possible effects of galvanic corrosion.
4.2 One method that is used to predict the effects of galvanic corrosion is to develop a galvanic series by arranging a list of the materials of interest in order of observed corrosion potentials in the environment and conditions of interest. The metal that will suffer increased corrosion in a galvanic couple in that environment can then be predicted from the relative position of the two metals in the series.
4.3 Types of Galvanic Series:
4.3.1 One type of Galvanic Series lists the metals of interest in order of their corrosion potentials, starting with the most active (electronegative) and proceeding in order to the most noble (electropositive). The potentials themselves (versus an appropriate reference half-cell) are listed so that the potential difference between metals in the series can be determined. This type of Galvanic Series has been put in graphical form as a series of bars displaying the range of potentials exhibited by the metal listed opposite each bar. Such a series is illustrated in Fig. 1.
4.4 Use of a Galvanic Series:
4.4.1 Generally, upon coupling two metals in the Galvanic Series, the more active (electronegative) metal will have a tendency to undergo increased corrosion while the more noble (electropositive) metal will have a tendency to undergo reduced corrosion.
4.4.2 Usually, the further apart two metals are in the series, and thus the greater the potential difference between them, the greater is the driving force f...
SCOPE
1.1 This guide covers the development of a galvanic series and its subsequent use as a method of predicting the effect that one metal can have upon another metal can when they are in electrical contact while immersed in an electrolyte. Suggestions for avoiding known pitfalls are included.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 5.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide7 pagesEnglish language
SIGNIFICANCE AND USE
3.1 This practice provides a methodology for measuring the duration of wetness on a sensing element mounted on a surface in a location of interest. Experience has shown that the sensing element reacts to factors that cause wetness in the same manner as the surface on which it is mounted.
3.2 Surface moisture plays a critical role in the corrosion of metals and the deterioration of nonmetallics. The deposition of moisture on a surface can be caused by atmospheric or climatic phenomena such as direct precipitation of rain or snow, condensation, the deliquescence (or at least the hygroscopic nature) of corrosion products or salt deposits on the surface, and others. A measure of atmospheric or climatic factors responsible for moisture deposition does not necessarily give an accurate indication of the TOW. For example, the surface temperature of an object may be above or below both the ambient and the dew point temperatures. As a result condensation will occur without an ambient meteorological indication that a surface has been subjected to a condensation cycle.
3.3 Structural design factors and orientation can be responsible for temperature differences and the consequent effect on TOW as discussed in 4.2. As a result, some surfaces may be shielded from rain or snow fall; drainage may be facilitated or prevented from given areas, and so forth. Therefore various components of a structure can be expected to perform differently depending on mass, orientation, air flow patterns, and so forth. A knowledge of TOW at different points on large structures can be useful in the interpretation of corrosion or other testing results.
3.4 In order to improve comparison of data obtained from test locations separated on a macrogeographical basis, a uniform orientation of sensor elements boldly exposed in the direction of the prevailing wind, at an angle of 30° above the horizontal is recommended. Elevation of the sensor above ground level should be recorded.
3.5 Although this...
SCOPE
1.1 This practice covers a technique for monitoring time-of-wetness (TOW) on surfaces exposed to cyclic atmospheric conditions which produce depositions of moisture.
1.2 The practice is also applicable for detecting and monitoring condensation within a wall or roof assembly and in test apparatus.
1.3 Exposure site calibration or characterization can be significantly enhanced if TOW is measured for comparison with other sites, particularly if this data is used in conjunction with other site-specific instrumentation techniques.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Standard7 pagesEnglish language
SIGNIFICANCE AND USE
5.1 In the past, ASTM specifications for low-alloy weathering steels, such as Specifications A242/A242M, A588/A588M, A606/A606M Type 4, A709/A709M Grade 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M stated that the atmospheric corrosion resistance of these steels is “approximately two times that of carbon structural steel with copper.” A footnote in the specifications stated that “two times carbon structural steel with copper is equivalent to four times carbon structural steel without copper (Cu 0.02 maximum).” Because such statements relating the corrosion resistance of weathering steels to that of other steels are imprecise and, more importantly, lack significance to the user (1 and 2),4 the present guide was prepared to describe more meaningful methods of estimating the atmospheric corrosion resistance of weathering steels.
5.2 The first method of this guide is intended for use in estimating the expected long-term atmospheric corrosion losses of specific grades of low-alloy steels in various environments, utilizing existing short-term atmospheric corrosion data for these grades of steel.
5.3 The second method of this guide is intended for use in estimating the relative atmospheric corrosion resistance of a specific heat of low-alloy steel, based on its chemical composition.
5.4 It is important to recognize that the methods presented here are based on calculations made from test data for flat, boldly exposed steel specimens. Atmospheric corrosion rates can be much higher when the weathering steel remains wet for prolonged periods of time, or is heavily contaminated with salt or other corrosive chemicals. Therefore, caution must be exercised in the application of these methods for prediction of long-term performance of actual structures.
SCOPE
1.1 This guide presents two methods for estimating the atmospheric corrosion resistance of low-alloy weathering steels, such as those described in Specifications A242/A242M, A588/A588M, A606/A606M Type 4, A709/A709M grades 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M. One method gives an estimate of the long-term thickness loss of a steel at a specific site based on results of short-term tests. The other gives an estimate of relative corrosion resistance based on chemical composition.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide9 pagesEnglish language
SIGNIFICANCE AND USE
5.1 Corrosion inhibitors continue to play a key role in controlling internal corrosion associated with oil and gas production and transportation. This results primarily from the industry’s extensive use of carbon and low alloy steels, which, for many applications, are economic materials of construction that generally exhibit poor corrosion resistance. As a consequence, there is a strong reliance on inhibitor deployment for achieving cost-effective corrosion control, especially for treating long flowlines and main export pipelines (1).5
5.2 For multiphase flow, the aqueous-oil-gas interphases can take any of an infinite number of possible forms. These forms are delineated into certain classes of interfacial distribution called flow regimes. The flow regimes depend on the inclination of the pipe (that is, vertical or horizontal), flow rate (based on production rate), and flow direction (that is, upward or downward). The common flow regimes in vertical upward flow, vertical downward flow, and horizontal flow are presented in Figs. 1-3 respectively (2, 3).
5.14 To develop an inhibitor selection strategy, in addition to inhibitor efficiency, several other key performance factors need to be evaluated: (1) water/oil partitioning, (2) solubility, (3) emulsification tendency, (4) foaming tendency, (5) thermal stability, (6) toxicity, and (7) compatibility with other additives/materials.
SCOPE
1.1 This guide covers some generally accepted laboratory methodologies that are used for evaluating corrosion inhibitors for oilfield and refinery applications in well defined flow conditions.
1.2 This guide does not cover detailed calculations and methods, but rather covers a range of approaches which have found application in inhibitor evaluation.
1.3 Only those methodologies that have found wide acceptance in inhibitor evaluation are considered in this guide.
1.4 This guide is intended to assist in the selection of methodologies that can be used for evaluating corrosion inhibitors.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory requirements prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Guide16 pagesEnglish language
Frequently Asked Questions
G01 is a Technical Committee within ASTM International. It is named "Corrosion of Metals" and is responsible for: The scope of the Committee shall be the promotion of knowledge, the stimulation of research, the collection of engineering data, and the development of standard test methods, practices, guides, classifications, specifications and terminology relating to corrosion and methods for corrosion-protection of metals. The work of this Committee will be coordinated with other ASTM Committees and other organization having mutual interest. This committee has published 462 standards.
G01 develops ASTM standards in the area of Information technology. The scope of work includes: The scope of the Committee shall be the promotion of knowledge, the stimulation of research, the collection of engineering data, and the development of standard test methods, practices, guides, classifications, specifications and terminology relating to corrosion and methods for corrosion-protection of metals. The work of this Committee will be coordinated with other ASTM Committees and other organization having mutual interest. Currently, there are 462 published standards from this technical committee.
ASTM is a standardization organization that develops and publishes standards to support industry, commerce, and regulatory requirements.
A Technical Committee (TC) in ASTM is a group of experts responsible for developing international standards in a specific technical area. TCs are composed of national member body delegates and work through consensus to create standards that meet global industry needs. Each TC may have subcommittees (SCs) and working groups (WGs) for specialized topics.