EN ISO 10271:2011

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Zobozdravstvo - Preskusne metode ugotavljanja korozije za kovinske materiale (ISO 10271:2011)Zahnheilkunde - Korrosionsprüfverfahren für metallische Werkstoffe (ISO 10271:2011)Médecine bucco-dentaire - Méthodes d'essai de corrosion des matériaux métalliques (ISO 10271:2011)Dentistry - Corrosion test methods for metallic materials (ISO 10271:2011)11.060.10Dental materialsICS:Ta slovenski standard je istoveten z:EN ISO 10271:2011SIST EN ISO 10271:2011en,fr,de01-december-2011SIST EN ISO 10271:2011SLOVENSKI
STANDARDSIST EN ISO 10271:2002/AC:2006SIST EN ISO 10271:20021DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN ISO 10271
August 2011 ICS 11.060.10 Supersedes EN ISO 10271:2001English Version
Dentistry - Corrosion test methods for metallic materials (ISO 10271:2011)
Médecine bucco-dentaire - Méthodes d'essai de corrosion des matériaux métalliques (ISO 10271:2011)
Zahnheilkunde - Korrosionsprüfverfahren für metallische Werkstoffe (ISO 10271:2011) This European Standard was approved by CEN on 29 July 2011.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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Reference numberISO 10271:2011(E)© ISO 2011
INTERNATIONAL STANDARD ISO10271Second edition2011-08-01Dentistry — Corrosion test methods for metallic materials Médecine bucco-dentaire — Méthodes d'essai de corrosion des matériaux métalliques
ISO 10271:2011(E)
©
ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel.
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ii © ISO 2011 – All rights reserved
ISO 10271:2011(E) © ISO 2011 – All rights reserved iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.1 3 Terms and definitions.1 4 Test methods.3 4.1 Static immersion test.3 4.2 Electrochemical test.6 4.3 Sulfide tarnish test (cyclic immersion).12 4.4 Sulfide tarnish test (static immersion).14 4.5 Static immersion test with periodic analysis.16 Annex A (informative)
Corrosion test method development.20 Bibliography.26
ISO 10271:2011(E) iv © ISO 2011 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 10271 was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2, Prosthodontic materials. This second edition cancels and replaces the first edition (ISO 10271:2001), which has been technically revised, in particular by the inclusion of two additional test methods. It also incorporates Technical Corrigendum ISO 10271:2001/Cor.1:2005. SIST EN ISO 10271:2011

ISO 10271:2011(E) © ISO 2011 – All rights reserved v Introduction This International Standard was developed from the original Technical Report (ISO/TR 10271) as a result of worldwide demand for standard test methods to determine acceptability of metallic materials for oral restorations in relation to corrosion. Specific qualitative and quantitative requirements for freedom from biological hazard are not included in this International Standard, but it is recommended that reference be made to ISO 10993-1 and ISO 7405 for assessing possible biological or toxicological hazards. The testing of the corrosion behavior of metallic materials in dentistry is complicated by the diversity of the materials themselves, their applications and the environment to which they are exposed. Variation occurs between devices and within the same device during the exposure time. The type of corrosion behavior or effect can also vary with exposure time. Accordingly, it is not possible to specify a single test capable of covering all situations, nor is it a practical proposition to define a test for each situation. This International Standard, therefore, gives detailed procedures for test methods that have been found to be of merit as evidenced by considerable use. This second edition differs from the first edition by the addition of two new test methods. To supplement the existing static immersion test, a static immersion test with periodic analysis has been added. A major reason for the addition of this test is that the rate of corrosion of most dental metallic materials varies over time. Thus, the aim of this supplementary test is to provide information on this variation in the corrosion of a dental metallic material. A classification scheme to interpret the rate of corrosion of a tested material with time (i.e. steady, decreasing, increasing) was not included as part of the static immersion test with periodic analysis. It is intended to monitor the use of the test through appropriate working groups of ISO/TC 106 to ascertain whether a classification scheme is needed in a future revision of this International Standard. To supplement the sulfide tarnish test (cyclic immersion), a sulfide tarnish test (static immersion) has also been added to this second edition of ISO 10271. This test has been used successfully for many years to evaluate the corrosion of silver alloys. In addition, an informative annex (Annex A) is provided that sets out a procedure for each element of the test system such that a consistent approach can be taken for the development of further test methods. Equally, it is recognized that any element can represent only the current recommendation, but changes in the future are unlikely to change the framework. It is not the purpose of this International Standard to propose corrosion test methods for specific applications or to set limits as precise as those in the standard relating to the type of product and its application. SIST EN ISO 10271:2011

INTERNATIONAL STANDARD ISO 10271:2011(E) © ISO 2011 – All rights reserved 1 Dentistry — Corrosion test methods for metallic materials 1 Scope This International Standard provides test methods and procedures to determine the corrosion behavior of metallic materials used in the oral cavity. It is intended that the test methods and procedures in this International Standard be referred to in the individual International Standards specifying such metallic materials. This International Standard is not applicable to instruments and dental amalgam and appliances for orthodontics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1042, Laboratory glassware — One-mark volumetric flasks ISO 1942, Dentistry — Vocabulary ISO 3585, Borosilicate glass 3.3 — Properties ISO 3696, Water for analytical laboratory use — Specification and test methods ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test ISO 7183, Compressed-air dryers — Specifications and testing 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply. 3.1 breakdown potential Ep least noble potential at which pitting or crevice corrosion, or both, initiates and propagates 3.2 corrosion physicochemical interaction between a metallic material and its environment that results in a partial or total destruction of the material or in a change of its properties SIST EN ISO 10271:2011

ISO 10271:2011(E) 2 © ISO 2011 – All rights reserved 3.3 corrosion potential Ecorr open-circuit potential measured under either service conditions, or laboratory conditions that closely approximate service conditions 3.4 corrosion product substance formed as a result of corrosion 3.5 crevice corrosion corrosion associated with and taking place in or near a narrow aperture or crevice 3.6 current density value of electric current per unit surface area flowing through a conductor 3.7 dynamic immersion test test in which the sample is exposed to a corrosive solution under conditions of relative motion between sample and solution 3.8 electrode potential potential difference between the sample and a reference electrode 3.9 electrolyte solution or liquid that conducts an electrical current by means of ions 3.10 open-circuit potential Eocp potential of an electrode measured with respect to a reference electrode or another electrode when no current flows 3.11 pitting corrosion localized corrosion which results in pits 3.12 potentiodynamic test test in which the electrode potential is varied at a preprogrammed rate and the relationship between current density and electrode potential is recorded 3.13 potentiostatic test test in which the electrode potential is maintained constant 3.14 sample totality of material for one type being tested, the group of all such specimens 3.15 set subgroup of the specimens of a sample SIST EN ISO 10271:2011

ISO 10271:2011(E) © ISO 2011 – All rights reserved 3 3.16 specimen individual single example of an object for testing 3.17 static immersion test test in which the sample is exposed to a corrosive solution under conditions of effectively no relative motion between sample and solution 3.18 stress corrosion corrosion resulting from the combined action of static tensile stress and an electrolyte 3.19 synthetic saliva test medium that simulates the chemistry of natural saliva 3.20 tarnish surface discoloration due to the chemical reaction between a metallic material and its environment 3.21 zero-current potential potential at which cathodic and anodic currents are equal 4 Test methods 4.1 Static immersion test 4.1.1 Information required Composition, including hazardous elements, in accordance with the appropriate ISO standard is required. 4.1.2 Application This is an accelerated test that is intended to provide quantitative data on the metallic ion released from metallic materials under in vitro conditions relevant to those expected in the oral cavity. 4.1.3 Reagents 4.1.3.1 Lactic acid (C3H6O3), 90 %, analytical grade. 4.1.3.2 Sodium chloride (NaCl), analytical grade. 4.1.3.3 Water, complying with grade 2 of ISO 3696. 4.1.3.4 Ethanol or methanol (C2H5OH or CH3OH), analytical grade. 4.1.3.5 Compressed air, oil- and water-free, complying with ISO 7183. 4.1.4 Apparatus 4.1.4.1 Containers, of borosilicate glass, complying with ISO 3585 and with dimensions of approximately 16 mm inner diameter by 160 mm in height. 4.1.4.2 pH meter, with a sensitivity of at least ±0,05 pH units. SIST EN ISO 10271:2011

ISO 10271:2011(E) 4 © ISO 2011 – All rights reserved 4.1.4.3 Chemical analysis instrumentation, capable of measuring ion concentration in µg/ml (e.g. ICP and AAS). 4.1.4.4 Micrometer gauge, accurate to 0,01 mm. 4.1.4.5 Silicon carbide paper, complying with ISO 6344-1. 4.1.4.6 Volumetric flasks, of borosilicate glass, 1 000 ml, class A, complying with ISO 1042. 4.1.5 Solution preparation Prepare an aqueous solution comprising 0,1 mol/l lactic acid and 0,1 mol/l sodium chloride immediately before use. For example, dissolve (10,0 ± 0,1) g 90 % C3H6O3 (4.1.3.1) and (5,85 ± 0,005) g NaCl (4.1.3.2) in approximately 300 ml of water (4.1.3.3). Transfer into a 1 000 ml volumetric flask (4.1.4.6) and fill to mark. The pH shall be 2,3 ± 0,1. If not, the solution shall be discarded and reagents checked. 4.1.6 Samples 4.1.6.1 Fabrication 4.1.6.1.1 Cast Specimens shall be cast in accordance with the manufacturer's recommendations. 4.1.6.1.2 Prefabricated Prefabricated parts/devices shall be used in the as-received condition. 4.1.6.1.3 Other Specimens prepared by other methods, e.g. machined, sintered, eroded, etc., shall be tested in the as-manufactured condition after suitable cleaning. 4.1.6.2 Sampling The number of specimens shall be sufficient to provide at least two parallel sets. (The number of specimens in a set may vary.) 4.1.6.3 Sample surface area The total surface area of the sample shall be at least 10 cm2 after preparation. 4.1.6.4 Preparation 4.1.6.4.1 Cast samples Remove any sprues, runners or other projections from surface. Blast surfaces with 125 µm pure alumina to remove investment. If recommended, heat-treat according to the manufacturer's instructions. In the case of metal-ceramic materials, heat-treat for 10 min at the highest firing temperature recommended by the metallic material manufacturer and bench cool. Remove at least 0,1 mm, measured using a measuring instrument [e.g. micrometer gauge (4.1.4.4)], from each surface using standard metallographic procedures unless specimens are being tested in the as-received SIST EN ISO 10271:2011

ISO 10271:2011(E) © ISO 2011 – All rights reserved 5 condition. Use fresh abrasive paper for each metallic material. Finish with P1200 wet silicon carbide paper (4.1.4.5). If the described procedure is not applicable, treat the surfaces according to the manufacturer's instructions for clinical use.
Determine each sample surface area to the nearest 1 %. Clean surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3). Dry with oil- and water-free compressed air (4.1.3.5). If a specimen contains any porosity visible on the surfaces being exposed to the solution, the specimen shall be rejected and replaced with a new one. 4.1.6.4.2 Machined, sintered, eroded or electroformed samples Heat-treat the specimens if recommended. Remove at least 0,1 mm, measured using a measuring instrument [e.g. micrometer gauge (4.1.4.4)], from each surface using standard metallographic procedures unless specimens are being tested in the as-received condition. Use fresh abrasive paper for each metallic material. Finish with P1200 wet silicon carbide paper (4.1.4.5). Determine each sample surface area to within ±0,1 cm2. Clean surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3). Dry with oil- and water-free compressed air (4.1.3.5). 4.1.6.4.3 Prefabricated parts/devices Treat the surfaces according to the manufacturer's instructions for clinical use. Determine each sample surface area to within ±0,1 cm2. Clean the surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3). Dry with oil- and water-free compressed air (4.1.3.5). 4.1.7 Test procedure Parallel specimen sets shall be treated in identical fashion. If a set consists of one specimen, it shall be placed in a container (4.1.4.1) such that it does not touch the container surface except in a minimum support line or point. If a set consists of two or more specimens, they may be placed in the same or a number of separate containers, but if more than one is placed in a container they shall not touch. Record the pH of the solution. Add the solution to each container sufficient to produce a ratio of 1 ml of solution per 1 cm2 of sample surface area. The specimens shall be covered completely by the solution. Record the volume of solution to an accuracy of 0,1 ml. Close the container to prevent evaporation of the solution. Maintain at (37 ± 1) °C for 7 d ± 1 h. Remove the specimens and record the pH of the residual solution. Use an additional container (4.1.4.1) to hold a reference solution to be maintained in parallel with the solutions containing the specimens. The reference solution shall be used to establish the impurity level for each element of interest in the solution. Add approximately the same volume of solution as used for the solutions containing the specimens and record the volume to an accuracy of 0,1 ml. Close the container to prevent evaporation of the solution and maintain at (37 ± 1 ) °C for the same time period as the solutions containing the specimens. SIST EN ISO 10271:2011

ISO 10271:2011(E) 6 © ISO 2011 – All rights reserved 4.1.8 Elemental analysis Use chemical analysis instrumentation (4.1.4.3) of adequate sensitivity. Analyze the solution qualitatively and quantitatively. Emphasis shall be on those elements indicated in 4.1.1, but if impurities are found in a concentration greater than 0,1 %, they shall also be reported. For each element of interest, subtract the value obtained for the element in the reference solution from the value obtained in the test solution. The elements boron, carbon, and nitrogen shall be disregarded. 4.1.9 Test report The test report shall contain the following information. a) Report the method of analysis and detection limits of all the analyzed elements. b) Report and justify any deviations from preparation of specimens (see 4.1.6.4) or test procedure (see 4.1.7). c) Report the number of specimens making up a set and the number of sets tested (see 4.1.6.2). d) From the elemental analysis of the corrosion solution (see 4.1.8), calculate and report the ion release for each element of each set (see 4.1.6.2) separately in µg/cm2/7 d. The elements indicated in 4.1.1 shall be reported as well as any others found. From this information, sum the ion release values for all the elements of each set to obtain the total metal ion release for the dental material. Average the results by dividing by the number of sets tested and report as the average total ion release for the dental material in µg/cm2/7 d. e) Report undissolved corrosion product like precipitates and discoloration of the specimen surface. 4.2 Electrochemical test 4.2.1 Information required Composition, including hazardous elements, in accordance with the appropriate material standard is required. 4.2.2 Application This test is intended to assess the corrosion susceptibility of metallic materials used in the oral cavity using potentiodynamic polarization. 4.2.3 Reagents 4.2.3.1 Lactic acid (C3H6O3), 90 %, chemically pure. 4.2.3.2 Sodium chloride (NaCl), analytical grade. 4.2.3.3 Sodium hydroxide (NaOH), analytical grade. 4.2.3.4 Water, complying with grade 2 of ISO 3696. 4.2.3.5 Argon or nitrogen gas, with a minimum purity of 99,99 %. 4.2.3.6 Ethanol or methanol (C2H5OH or CH3OH), analytical grade. 4.2.3.7 Acetone (C3H6O), analytical grade. SIST EN ISO 10271:2011

ISO 10271:2011(E) © ISO 2011 – All rights reserved 7 4.2.4 Apparatus 4.2.4.1 Test cell, temperature-controlled, of borosilicate glass, complying with ISO 3585 [a double-walled cell is unnecessary if the test is carried out at (23 ± 2) °C]. 4.2.4.2 Scanning potentiostat, potential range ±1 600 mV, current output range 10–9 A to 10–1 A. 4.2.4.3 Potential measuring instrument, with input impedance > 1011 W and sensitivity/accuracy able to detect a change of 1 mV over a potential change of ±1 600 mV. 4.2.4.4 Current-measuring instrument, capable of measuring a current to within 1 % of the absolute value over a current range between 10–9 A and 10–1 A. 4.2.4.5 Working electrode (specimen holder). 4.2.4.6 Counter electrode(s), composed of high-purity vitreous carbon or platinum. 4.2.4.7 Reference electrode, either saturated calomel electrode (SCE) or Ag/AgCl electrode [saturated silver chloride electrode (SSE)]. 4.2.4.8 pH meter, with a sensitivity of ±0,05 pH units. 4.2.4.9 Silicon carbide paper, complying with ISO 6344-1. 4.2.4.10 Diamond paste,1 µm. 4.2.4.11 Micrometer gauge, accurate to 0,01 mm. 4.2.4.12 Light microscope, minimum magnification of ¥50. 4.2.5 Solution preparation Dissolve 9,0 g NaCl (4.2.3.2) in approximately 950 ml water (4.2.3.4). Adjust to pH 7,4 ± 0,1 using 1 % C3H6O3 (4.2.3.1) or 4 % NaOH (4.2.3.3). Dilute with water to 1 000 ml. 4.2.6 Samples 4.2.6.1 Fabrication 4.2.6.1.1 Cast Specimens shall be cast in accordance with the manufacturer's recommendations. 4.2.6.1.2 Prefabricated Prefabricated parts/devices shall be used in the as-received condition. 4.2.6.1.3 Other Specimens prepared by other methods, e.g. machined, sintered, eroded, etc., shall be tested in the as-manufactured condition after suitable cleaning. 4.2.6.2 Sampling At least four specimens shall be tested. SIST EN ISO 10271:2011

ISO 10271:2011(E) 8 © ISO 2011 – All rights reserved 4.2.6.3 Sample surface area The surface area of each specimen shall be not less than 0,1 cm2 after preparation. 4.2.6.4 Preparation Remove any sprues, runners or other projections from surface. Blast surfaces with 125 µm pure alumina to remove investment. If recommended, heat-treat according to the manufacturer's instructions. In the case of metal-ceramic materials, heat-treat for 10 min at the highest firing temperature recommended by the metallic material manufacturer and bench cool. Specimens shall be prepared with one flat surface exposed. A suitable contact shall be provided for connection to the electrochemical apparatus. The working electrode shall be prepared in a way that ensures the absence of crevices. The recommended procedure is that of embedding in epoxy resin that does not exhibit loss of electrical insulation during immersion. Instead of embedding, a specimen holder (4.2.4.5) may be used if the absence of crevices is confirmed by specimen examination after the test. Remove at least 0,1 mm, measured using a measuring instrument [e.g. micrometer gauge (4.2.4.11)], from each free surface using standard metallographic procedures unless specimens are being tested in the as-received condition. Use fresh abrasive paper for each metallic material. Finish with P1200 wet silicon carbide paper (4.2.4.9) and end with 1 µm diamond paste (4.2.4.10). If the described procedure is not applicable, treat the surfaces according to the manufacturer's instructions for clinical use. Examine with a light microscope at ¥50 (4.2.4.12) for cracks or crevices at the specimen/resin interface. Replace the specimen if any cracks or crevices are found. Determine the area exposed to solution of each specimen to within 0,01 cm2. Manually clean surface with acetone (4.2.3.7). Clean surfaces ultrasonically in the following sequence: alcohol (4.2.3.6) and water (4.2.3.4) for 2 min each. Store in water (4.2.3.4) until transferred to test cell. 4.2.7 Test procedure 4.2.7.1 Test set-up An example of an electrochemical measuring circuit is shown in Figure 1. An example of an electrolytic cell is shown in Figure 2. Fill test cell with electrolyte. Test at room temperature (23 ± 2) °C. If there is a phase transition between room temperature and 37 °C, then a test temperature of (37 ± 1) °C shall be used. Place counter electrode(s) in the test cell followed by the reference electrode. Then place the working electrode in the test cell without immersion. Activate the magnetic stirrer. Bubble oxygen-free nitrogen or argon at a rate of about 100 cm3/min through the electrolyte for at least 30 min. Immerse the working electrode in the electrolyte. Adjust the reference electrode. Adjust gas flow-rate to give a slight bubbling. Begin measurement procedure.
ISO 10271:2011(E) © ISO 2011 – All rights reserved 9 Key 1 potentiostat 2 counter electrode 3 reference electrode 4 working electrode
a Current measurement. b Potential measurement. Figure 1 — Schematic diagram of measuring circuit
Key 1 thermometer 5 reference electrode [saturated calomel electrode (SCE)] 9 magnetic agitator (motor) 2 counter electrode 6 saturated solution of KCl 10 double-walled vessel 3 working electrode 7 Luggin capillary 11 electrolyte 4 electrolytic bridge 8 magnetic stirrer (PTFE-coated) 12 bubbler (using nitrogen) a Gas outlet. b Water inlet. c Water outlet. Figure 2 — Schematic diagram of electrolytic cell SIST EN ISO 10271:2011

ISO 10271:2011(E) 10 © ISO 2011 – All rights reserved 4.2.7.2 Open-circuit potential measurement Record the open-circuit potential versus time curve for 2 h. Determine the open-circuit potential (Eocp) in mV (SCE) after immersion for 2 h ± 6 min. An example of a potential versus time curve is shown in Figure 3. 4.2.7.3 Potential measurements (anodic polarization) Start the potentiodynamic scan 5 min after finishing the open-circuit potential measurement at Eocp minus 150 mV. The potentiodynamic sweep rate should be 1 mV/s up to a current density threshold two decades greater than the current density recorded at breakdown or a potential of + 1 500 mV (SCE) [or breakdown potential (Ep) + 300 mV]. Record the curve of potential versus logarithm of current density. A reverse scan back to the original potential may be used to obtain information on pitting corrosion. An example of a potential versus log current density curve is shown in Figure 4.
Key X time, in hours Y potential, Eocp, in millivolts (SCE) Figure 3 — Open-circuit potential versus time SIST EN ISO 10271:2011

ISO 10271:2011(E) © ISO 2011 – All rights reserved 11
Key X potential, in millivolts (SCE) Y log current, expressed in amperes per square centimetre SCE saturated calomel electrode Eocp open-circuit potential, expressed in millivolts (SCE) Eocp − 150 mv potential at the open-circuit potential minus 150 mV, expressed in millivolts (SCE) Ez zero-current potential, expressed in millivolts (SCE) Ec1 first active peak potential, expressed in millivolts (SCE) E300 potential at the open-circuit potential plus 300 mV, expressed in millivolts (SCE) Ec2 second active peak potential, expressed in millivolts (SCE) Ep breakdown potential, expressed in millivolts (SCE) Ic1 current density, expressed in amperes per square centimetre that corresponds to Ec1 I300 current density, expressed in amperes per square centimetre that corresponds to E300 Ic2 current density, expressed in amperes per square centimetre that corresponds to Ec2 Figure 4 — Log current density versus potential
4.2.8 Test report The test report shall contain the following information: a) identity of the test metallic material; b) details of heat treatment, if applicable; c) test temperature (23 ± 2) °C; if 37 °C is used, the reason for this choice; d) description of any deviations from preparation of specimens or test procedure; SIST EN ISO 10271:2011

ISO 10271:2011(E) 12 © ISO 2011 – All rights reserved e) open-circuit potential (Eocp), expressed in millivolts (SCE); f) potential versus log current density curve or potential versus current density curve; g) zero-current potential, Ez, expressed in millivolts (SCE); h) breakdown potential, Ep, expressed in millivolts (SCE), with the corresponding current density, Ip, expressed in amperes per square centimetre; i) active peak potentials, Ec, expressed in millivolts (SCE) between Ez and Ep with the corresponding current density, Ic, expressed in amperes per square centimetre; j) current density, I300, expressed in amperes per square centimetre at potential of (Ez + 300) mV (SCE); k) description of any significant changes of the electrolyte or the metallic material surface. If a reference electrode other than a saturated calomel electrode (SCE) is used, the reported potential values shall be converted to millivolts (SCE). 4.3 Sulfide tarnish test (cyclic immersion) 4.3.1 Information required Composition, including hazardous elements, in accordance with the appropriate ISO material standard is required. 4.3.2 Application This test method is suitable for dental metallic materials that are susceptible to sulfide tarnish, such as those containing silver. 4.3.3 Reagents 4.3.3.1 Sodium sulfide hydrate (approximately 35 % Na2S), analytical grade. 4.3.3.2 Water, complying with grade 2 of ISO 3696. 4.3.3.3 Ethanol or methanol (C2H5OH or CH3
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