ASTM E415-21

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E415 − 17 E415 − 21
Standard Test Method for
Analysis of Carbon and Low-Alloy Steel by Spark Atomic
Emission Spectrometry
This standard is issued under the fixed designation E415; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the simultaneous determination of 21 alloying and residual elements in carbon and low-alloy steels
by spark atomic emission vacuum spectrometry in the mass fraction ranges shown Note 1.
Composition Range, %
Applicable
Element Range, Quantitative Range,
B
Mass Fraction Mass Fraction %
A
%
Aluminum 0 to 0.093 0.006 to 0.093
Antimony 0 to 0.027 0.006 to 0.027
Arsenic 0 to 0.1 0.003 to 0.1
Boron 0 to 0.007 0.0004 to 0.007
Calcium 0 to 0.003 0.002 to 0.003
Carbon 0 to 1.1 0.02 to 1.1
Chromium 0 to 8.2 0.007 to 8.14
Cobalt 0 to 0.20 0.006 to 0.20
Copper 0 to 0.5 0.006 to 0.5
C
Lead 0 to 0.2 0.002 to 0.2
Manganese 0 to 2.0 0.03 to 2.0
Molybdenum 0 to 1.3 0.007 to 1.3
Nickel 0 to 5.0 0.006 to 5.0
Niobium 0 to 0.12 0.003 to 0.12
Nitrogen 0 to 0.015 0.01 to 0.055
Phosphorous 0 to 0.085 0.006 to 0.085
Silicon 0 to 1.54 0.02 to 1.54
Sulfur 0 to 0.055 0.001 to 0.055
Tin 0 to 0.061 0.005 to 0.061
Titanium 0 to 0.2 0.001 to 0.2
Vanadium 0 to 0.3 0.003 to 0.3
Zirconium 0 to 0.05 0.01 to 0.05
A
Applicable range in accordance with Guide E1763 for results reported in accordance with Practice E1950.
B
Quantitative range in accordance with Practice E1601.
C
Newly added element, refer to 15.4 and Table 3.
NOTE 1—The mass fraction ranges of the elements listed have been established through cooperative testing of reference materials.
1.2 This test method covers analysis of specimens having a diameter adequate to overlap and seal the bore of the spark stand
This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.01 on Iron, Steel, and Ferroalloys.
Current edition approved May 15, 2017Oct. 1, 2021. Published June 2017November 2021. Originally approved in 1971. Last previous edition approved in 20152017 as
E415 – 15.E415 – 17. DOI: 10.1520/E0415-15.10.1520/E0415-21.
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:E01-1122. Contact ASTM Customer
Service at service@astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E415 − 21
opening. The specimen thickness can vary significantly according to the design of the spectrometer stand, but a thickness between
10 mm and 38 mm has been found to be most practical.
1.3 This test method covers the routine control analysis in iron and steelmaking operations and the analysis of processed material.
It is designed for chill-cast, rolled, and forged specimens. Better performance is expected when reference materials and specimens
are of similar metallurgical condition and composition. However, it is not required for all applications of 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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E305 Practice for Establishing and Controlling Spark Atomic Emission Spectrochemical Analytical Curves
E350 Test Methods for Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought
Iron
E406 Practice for Using Controlled Atmospheres in Atomic Emission Spectrometry
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by
Various Combustion and Inert Gas Fusion Techniques
E1329 Practice for Verification and Use of Control Charts in Spectrochemical Analysis (Withdrawn 2019)
E1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
E1763 Guide for Interpretation and Use of Results from Interlaboratory Testing of Chemical Analysis Methods (Withdrawn
2015)
E1806 Practice for Sampling Steel and Iron for Determination of Chemical Composition
E1950 Practice for Reporting Results from Methods of Chemical Analysis
E2972 Guide for Production, Testing, and Value Assignment of In-House Reference Materials for Metals, Ores, and Other
Related Materials
2.2 Other ASTM DocumentsDocument:
ASTM MNL 7 Manual on Presentation of Data and Control Chart Analysis
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology E135.
4. Summary of Test Method
4.1 A capacitor discharge is produced between the flat, ground surface of the disk specimen and a conically shaped electrode. The
discharge is terminated at a predetermined intensity time integral of a selected iron line, or at a predetermined time, and the relative
radiant energies of the analytical lines are recorded. The most sensitive lines of arsenic, boron, carbon, nitrogen, phosphorus, sulfur,
and tin lie in the vacuum ultraviolet region. The absorption of the radiation by air in this region is overcome by evacuating the
spectrometer or by use of a vacuum ultraviolet (VUV) transparent gas and flushing the spark chamber with argon.
5. Significance and Use
5.1 This test method for the spectrometric analysis of metals and alloys is primarily intended to test such materials for compliance
with compositional specifications. It is assumed that all who use this test method will be analysts capable of performing common
laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
ASTM Manual Series, ASTM International, 8th edition, 2010.
E415 − 21
6. Apparatus
6.1 Sampling Devices:
6.1.1 Refer to Practice E1806 for devices and practices to sample liquid and solid iron and steel.
6.2 Excitation Source, capable of providing electrical parameters to spark a sample. See 11.1 for details.
6.3 Spark Chamber, automatically flushed with argon. The spark chamber shall be mounted directly on the spectrometer and shall
be provided with a spark stand to hold a flat specimen and a lower counter electrode of rod form.
6.3.1 Follow the manufacturer’s recommendations for cleaning the spark chamber. During continuous operation, this typically
should be done every 24 h. Follow the manufacturer’s recommendations for cleaning the entrance lens or window (verifier data
or other reference sample intensity data can typically indicate when this is necessary).
6.4 Spectral Lines—Table 1 lists spectral lines and internal standards usable for carbon and low alloy steel. The spectrometer must
be able to measure at least one of the listed spectral lines for each of the listed elements. Spectral lines other than those listed in
Table 1 may be used provided it can be shown experimentally that equivalent precision and accuracy are obtained.
6.5 Measuring System, spectrometer capable of converting light intensities to measurable electrical signals. The measuring system
may consist of one of the following configurations:
6.5.1 A photomultiplier (PMT) array having individual voltage adjustments, capacitors in which the output of each photomultiplier
is stored, a voltage measuring system to register the voltages on the capacitors either directly or indirectly, and the necessary
switching arrangements to provide the desired sequence of operation.
6.5.2 A semiconductor detector array (CCD or CMOS), pixel selection electronics to reset the pixels and to transport the voltage
of an individual pixel to one or more output ports of the detector arrays, and a voltage measuring system to register the voltage
of said output ports.
6.5.3 A hybrid design using both photomultipliers and semiconductor arrays.
6.6 Optical Path—If the instrument is operated using a VUV transparent gas, check the manufacturer’s suggested gas purity. It
may be necessary to have a gas purification system consisting of a circulation pump and a cleaning cartridge to keep the O (g)
residual <500 ng/g and H O (g) residual <1 μg ⁄g and remove impurities of nitrogen and hydrocarbons. If the instrument is using
a vacuum pump, it should be capable of maintaining a vacuum of 3.33 Pa (25 μm Hg) or less.
3 3
NOTE 2—A pump with a displacement of at least 0.23 m /min (8 ft /min) is usually adequate.
6.7 Gas System, consisting of an argon supply with pressure and flow regulation. Automatic sequencing shall be provided to
actuate the flow at a given rate for a specific time interval. The flow rate may be manually or automatically set. The argon system
shall be in accordance with Practice E406.
7. Reagents and Materials
7.1 Counter Electrodes—The counter electrodes can be silver or tungsten rods, or other material, provided it can be shown
experimentally that equivalent precision and bias are obtained. The rods can vary in diameter from 1.5 mm to 6.5 mm (depending
on the instrument design) and typically are machined to a 90° or 120° angled tip.
7.1.1 A black deposit will collect on the tip of the electrode. This deposit should be removed between specimens (typically with
a wire brush). If not removed, it can reduce the overall intensity of the spectral radiation or transfer slight amounts of contamination
between specimens, or both. The number of acceptable burns on an electrode varies from one instrument to another, and should
be established in each laboratory.
NOTE 3—It has been reported that thousands of burns can be performed on a tungsten electrode before replacement is necessary.
E415 − 21
TABLE 1 Internal Standard and Analytical Lines
Wavelength, Line Possible
Element
A B
λ, nm Classification Interference
Aluminum 396.15 I Mo
394.40 I V, Mn, Mo, Ni
308.22 I V, Mn
Antimony 217.6 I Ni, Nb, Mn, W
Arsenic 189.04 I V, Cr
197.20 I Mo, W
193.76 I Mn
Boron 345.13 II
182.64 I S, Mn, Mo
182.59 I W, Mn, Cu
Calcium 393.37 II
396.85 II Nb
Carbon 165.81 I Cr
193.09 I Al
Chromium 312.26 II V
313.21 II
425.44 I
298.92 II Mn, V, Ni, Nb, Mo
267.72 II Mn, Mo, W
Cobalt 345.35 I Cr, Mo
228.62 II Ni, Cr
258.03 II Fe, Mn, W
Copper 212.3 II Si
324.75 I Mn, Nb
327.40 I Nb
224.26 II W, Ni
213.60 II Mo, Cr
510.55 I W
136.14 II
157.40 II
172.24 II
174.28 II
179.34 I
182.88 II
205.13 I
216.20 I
217.81 I
218.65 II
226.76 II
235.12 II
239.15 I
277.21 I
281.33 I
285.18 I
296.69 II
297.05 I
299.95 I
300.81 I
303.74 I
304.76 I
Iron (IS) 305.91 I
316.79 I
517.16 I
321.33 II
487.21 I
458.38 II
413.70 I
410.75 I
383.63 I
363.83 I
339.93 I
328.68 I
308.37 I
282.33 I
249.59 I
E415 − 21
TABLE 1 Continued
Wavelength, Line Possible
Element
A B
λ, nm Classification Interference
226.76 II
218.65 II
216.20 I
193.53 II
190.48 I
187.75 II
149.65 II
271.44 II
273.07 II
Co
492.39 I
Lead 405.75 I Mn
Manganese 293.31 II Cr, Mo, Ni
255.86 II Zr
263.82 II Al, W
Molybdenum 379.83 II
Mn
202.03 II
277.54 I Cu, V, Co, Mn
281.61 II Mn
386.41 I V, Cr
Nickel 471.44 I
227.73 II
341.48 I
352.45 I
231.60 II Co, Ti
227.02 II Nb, W
243.79 II Co, Fe, Ni
Niobium 313.08 II Ti, V
319.50 II Mo, Al, V
Nitrogen 149.26 I Fe, Ti, Si, Mn, Cu, Ni and nitride
forming elements such as Ti
Phosphorus 178.29 I Mo
Silicon 288.16 I Mo, Cr, W
251.61 I Fe, V
212.41 I Mo, Ni, V, Cu, Nb
390.55 I Cr, Cu, W, Ti
Sulfur 180.73 I Mn
Tin 147.52 II
189.99 II Mn, Mo, Al
Titanium 308.80 I Cu, Co
337.28 II Nb
Tungsten 324.20 II Nb
400.88 I
202.99 II Ti, V, Mn
220.50 II Co
Vanadium 437.92 I
310.23 II Fe, Mo, Nb, Ni
Zirconium 468.78 I
349.62 II
343.82 II W
206.19 II W
A
The numerals I or II in the line classification column indicate that the line has been classified in a term array and definitely assigned to the normal atom (I) or to the singly
ionized atom (II).
B
Interferences are dependent upon instrument design, spectrum line choices, and excitation conditions, and those listed require confirmation based upon specimens
selected especially to demonstrate suspected interferences.
7.2 Inert Gas, Argon, in accordance with Practice E406.
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8. Reference Materials
8.1 Certified Reference Materials (CRMs)—These are available from the National Institute of Standards and Technology (NIST)
and other sources and span all or part of the mass fraction ranges listed in 1.1. They are used to calibrate the spectrometer for the
elements of interest or to validate the performance of the test method. It is not recommended to use CRMs as verifiers or to
establish the repeatability of the chemical measurement process.
NOTE 4—Certified Reference Materials manufactured by NIST are trademarked with the name, “Standard Reference Material.”
8.2 Reference Materials (RMs)—These are available from multiple suppliers or can be developed in house. Reference Materials
are typically used in control procedures (verifiers) and in drift correction (standardization) of the spectrometer, and they may be
useful in calibrations. These reference materials shall be homogenous and contain appropriate mass fractions of each element for
the intended purpose. Refer to Guide E2972 for production of your own reference materials.
8.3 Several issues can impact the selection and use of CRMs and RMs:
8.3.1 Samples and reference materials may exhibit differences in metallurgical structure, in particular having different sizes,
compositions, and distributions of inclusions. Inhomogeneous distribution of inclusions can worsen repeatability of individual
measurements of elements found in the inclusions. Some inclusions may be removed during preburn steps prior to integration of
intensities, causing low results. Typical samples can be used to determine repeatability of individual measurements to yield
estimates consistent with performance for actual samples.
8.3.2 For certain elements, there may be no available reference materials with metallurgical structure similar to typical samples.
Therefore, calibrations may be biased. It is recommended to validate results using typical samples analyzed using Test Methods
E350 and E1019.
9. Preparation of Specimens and Reference Materials
9.1 The specimens and reference materials shall be prepared in the same manner. A specimen cut from a large sample section shall
be of sufficient size and thickness for preparation and to properly fit the spectrometer stand. A 10-mm to 38-mm thick specimen
is normally most practical.
9.2 Ensure that the specimens are free from voids and pits in the region to be measured (Note 5). Initially, grind the surface with
a 50-grit to 80-grit abrasive belt or disc (wet or dry) or mill the surface. If wet grinding, perform the final grind with a dry abrasive
belt or disc. A finer abrasive grinding media (for example, 120-grit) may be used for the final grind, but is not essential.
NOTE 5—Specimen porosity is undesirable because it leads to the improper “diffuse-type” rather than the desired “concentrated-type” discharge. The
specimen surface should be kept clean because the specimen is the electron emitter, and electron emission is inhibited by oily, dirty surfaces.
9.2.1 Reference materials and specimens shall be refinished dry on an abrasive belt or disc before being remeasured on the same
area.
10. Preparation of Apparatus
NOTE 6—The instructions given in this test method apply to most spectrometers. However, some settings and adjustments may require modification, and
additional preparation of the equipment may be required. It is not within the scope of an ASTM test method to prescribe the minute details of the apparatus
preparation, which may differ not only for each manufacturer, but also for different equipment from the same manufacturer. For a description of and
further details of operation for a particular spectrometer, refer to the manufacturer’s manual(s).
10.1 Program the spectrometer to use the internal standard lines and one of the analytical lines for each element listed in Table
1. Multiple lines may be used for a given element (for example, nickel) depending on the mass fraction range and the individual
spectrometer software.
10.2 Test the positioning of the spectrometer entrance slit to ensure that peak radiation is entering the spectrometer chamber. This
shall be done initially and as often as necessary to maintain proper entrance slit alignment. Follow the manufacturer’s
recommended procedures. The laboratory will determine the frequency of positioning the alignment based on instrument
performance.
E415 − 21
10.3 Exit slit positioning and alignment is normally performed by the manufacturer at spectrometer assembly. Under normal
circumstances, further exit slit alignment is not necessary (Note 7).
NOTE 7—The manner and frequency of positioning or checking the position of the exit slits will depend on factors such as the type of spectrometer, the
variety of analytical problems encountered, and the frequency of use. Each laboratory should establish a suitable check procedure utilizing qualified
service engineers.
11. Burn and Exposure
11.1 Electrical Parameters:
11.1.1 Burn parameters are normally established by the spectrometer manufacturer. The following ranges are historical guidelines
and newer instruments may vary from these:
Triggered Capacitor Discharge
Capacitance, μF 10 to 15
Inductance, μH 50 to 70
Resistance, Ω 3 to 5
Potential, V 940 to 1000
Current, A, r-f 0.3 to 0.8
Number of discharges 60
11.1.2 When parameter values are established, maintain them carefully. The variation of the power supply voltage shall not exceed
65 % and preferably should be held within 62 %.
11.1.3 Initiation Circuit—The initiator circuit parameters shall be adequate to uniformly trigger the capacitor discharge. The
following settings are historical guidelines and newer instruments may vary from these:
Capacitance, μF 0.0025
Inductance, μH residual
Resistance, Ω 2.5
Peak voltage, V 18 000
11.1.4 Other Electrical Parameters—Excitation units, on which the precise parameters given in 11.1.1 and 11.1.3 are not
available, may be used provided that it can be shown experimentally that equivalent precision and accuracy are obtained.
11.2 Burn and Measurement Conditions—The following ranges are normally adequate:
Argon flush period, s 5 to 15
Preburn period, s 5 to 20
Exposure period, s 3 to 30
Argon flow ft /h L/min
Flush 5 to 45 2.5 to 25
Preburn 5 to 45 2.5 to 25
Exposure 5 to 30 2.5 to 15
11.2.1 Select preburn and exposure periods after a study of volatization rates during specimen burns. Once established, maintain
the parameters consistently.
11.2.2 A high-purity argon atmosphere is required at the analytical gap. Molecular gas impurities, such as nitrogen, oxygen,
hydrocarbons, or water vapor, either in the gas system or from improperly prepared specimens, should be minimized.
11.3 Electrode System—The specimen, electrically negative, serves as one electrode. The opposite electrode is a tungs
...