ASTM_A_262_-_15.pdf

Designation:A26215Standard Practices forDetecting Susceptibility to Intergranular Attack in AusteniticStainless Steels1This standard is issued under the fixed designation A262;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 These practices cover the following five tests:1.1.1 Practice AOxalic Acid Etch Test for Classificationof Etch Structures of Austenitic Stainless Steels(Sections 4 to13,inclusive),1.1.2 Practice BFerric Sulfate-Sulfuric Acid Test for De-tecting Susceptibility to Intergranular Attack in AusteniticStainless Steels(Sections 14 to 25,inclusive),1.1.3 Practice CNitric Acid Test for Detecting Suscepti-bility to Intergranular Attack in Austenitic Stainless Steels(Sections 26 to 36,inclusive),1.1.4 Practice ECopperCopper SulfateSulfuric AcidTest for Detecting Susceptibility to Intergranular Attack inAustenitic Stainless Steels(Sections 37 to 46,inclusive),and1.1.5 Practice FCopperCopper Sulfate50%SulfuricAcid Test for Detecting Susceptibility to Intergranular Attackin Molybdenum-Bearing Austenitic Stainless Steels(Sections47 to 58,inclusive).1.2 The Oxalic Acid Etch Test is a rapid method ofidentifying,by simple etching,those specimens of certainstainless steel grades that are essentially free of susceptibilityto intergranular attack associated with chromium carbideprecipitates.These specimens will have low corrosion rates incertain corrosion tests and therefore can be eliminated(screened)from testing as“acceptable.”The etch test isapplicable only to those grades listed in the individual hot acidtests and classifies the specimens either as“acceptable”or as“suspect.”1.3 The ferric sulfate-sulfuric acid test,the coppercoppersulfate50%sulfuric acid test,and the nitric acid test are basedon weight loss determinations and,thus,provide a quantitativemeasure of the relative performance of specimens evaluated.Incontrast,the coppercopper sulfate16%sulfuric acid test isbased on visual examination of bend specimens and,therefore,classifies the specimens only as acceptable or nonacceptable.1.4 The presence or absence of intergranular attack in thesetests is not necessarily a measure of the performance of thematerial in other corrosive environments.These tests do notprovide a basis for predicting resistance to forms of corrosionother than intergranular,such as general corrosion,pitting,orstress-corrosion cracking.NOTE1See Appendix X1 for information regarding test selection.1.5 The values stated in SI units are to be regarded asstandard.The inch-pound equivalents are in parentheses andmay be approximate.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Some specifichazards statements are given in 10.1,20.1.1,20.1.9,31.3,34.4,53.1.1,and 53.1.10.2.Referenced Documents2.1 ASTM Standards:2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA380/A380M Practice for Cleaning,Descaling,and Passi-vation of Stainless Steel Parts,Equipment,and SystemsD1193 Specification for Reagent WaterE3 Guide for Preparation of Metallographic Specimens2.2 ASME Code:3ASME Boiler&Pressure Vessel Code,Section IX2.3 ACS Specifications:4Reagent Chemicals,Specifications and Procedures1These practices are under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and RelatedAlloys and are the direct responsibility of SubcommitteeA01.14 on Methods of Corrosion Testing.Current edition approved Sept.1,2015.Published September 2015.Originallyapproved in 1943.Last previous edition approved in 2014 as A262 14.DOI:10.1520/A0262-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers(ASME),ASMEInternational Headquarters,Two Park Ave.,New York,NY 10016-5990,http:/www.asme.org.4Available fromAmerican Chemical Society(ACS),1155 Sixteenth Street,NW,Washington,DC 20036,http:/www.acs.org*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.4 ISO Standard:5ISO 3651-2 Determination of Resistance to IntergranularCorrosion of Stainless SteelsPart 2:Ferritic,Austenitic,and Ferritic-Austenitic(Duplex)Stainless SteelsCorrosion Test in Media Containing Sulfuric Acid3.Purity of Reagents3.1 Purity of ReagentsReagen