ASTM B858-06(2018) Standard Test Method for Ammonia Vapor Test for Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys.pdf

1、Designation: B858 06 (Reapproved 2018)Standard Test Method forAmmonia Vapor Test for Determining Susceptibility toStress Corrosion Cracking in Copper Alloys1This standard is issued under the fixed designation B858; the number immediately following the designation indicates the year oforiginal adopti

2、on 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.1. Scope1.1 This test method describes a procedure to determine thepresence of residua

3、l stresses in wrought copper alloy productsthat may lead to stress corrosion cracking. An ammonia vaporatmosphere is used as an accelerated test.1.2 This test method is only suitable for products fabricatedfrom copper alloys that are known to be susceptible to stresscorrosion cracking in ammonia vap

4、or atmospheres. It is in-tended to create an environmental condition of reproducibleseverity.NOTE 1It is well known that the critical step in the crackingmechanism is the development of an environment in the condensate filmthat occurs on the surface of the test specimen, and is rich in coppercomplex

5、 ions.1.3 The severity of this test method depends upon the pH ofthe corrosive solution. In Annex A1 are given four differentatmospheres to which the product may be exposed, and theappropriate pH of the solution to be used for the test,depending on the risk level associated with the intendedapplicat

6、ion.1.3.1 The appropriate pH value for the test shall be specifiedin the product specification, or as per established agreementbetween the supplier and purchaser, with respect to the alloyand its intended application.1.4 UnitsThe values stated in SI units are to be regardedas standard. No other unit

7、s of measurement are included in thisstandard.1.5 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, health, and environmental practices and deter-mine the applic

8、ability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by th

9、e World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B154 Test Method for Mercurous Nitrate Test for CopperAlloysB846 Terminology for Copper and Copper AlloysD1193 Specification for Reagent Water3. Terminology3.1 For definitions of terms re

10、lated to copper and copperalloys, refer to Terminology B846.3.2 Definitions:3.2.1 applied stress, nstress in a body as a result ofapplication of an external load.4. Summary of Test Method4.1 The prepared test specimen is placed in a closedcontainer and exposed to ammonia vapor with a specific pH ata

11、mbient temperature for 24 h. Upon removal from the testatmosphere, the test specimen is examined for the presence ofcracks.5. Significance and Use5.1 This test method is an accelerated test to determine if acopper alloy product will be susceptible to stress-corrosioncracking when exposed to a partic

12、ular atmospheric conditionduring service with the appropriate risk levelsee Annex A1.5.1.1 This test method is generally intended to determine ifa copper alloy product will crack because of internal stresseswhen subjected to the test, and is not intended for testingassemblies under applied stress. I

13、f used for this purpose, it shallbe for information only and not a cause for rejection of theassembly, its component parts, or the original mill product.1This test method is under the jurisdiction of ASTM Committee B05 on Copperand Copper Alloys and is the direct responsibility of Subcommittee B05.0

14、6 onMethods of Test.Current edition approved March 1, 2018. Published March 2018. Originallyapproved in 1995. Last previous edition approved in 2012 as B858 06 (2012).DOI: 10.1520/B0858-06R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser

15、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance

16、with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.16. Apparatus6.1 pH meter.6.2 Closed ve

17、ssel, such as a desiccator.6.3 Equipment for examining test pieces at 10 to 15magnification.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onA

18、nalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherwis

19、e indicated, referencesto water shall be understood to mean reagent water as definedby Type IV or better, of Specification D1193.7.3 Ammonium Chloride Solution (4N)Dissolve 107 g ofammonium chloride (NH4Cl) in water and dilute to 500 mL.Store the solution in a closed vessel.7.4 Hydrogen Peroxide (H2

20、O2), 30 to 35 % technical grade.(WarningHydrogen peroxide in high concentrations cancause severe skin burns. Use of proper safety equipment isadvised.)7.5 Sodium Hydroxide Solution (300 to 500 g/L)Dissolve300 to 500 g of sodium hydroxide (NaOH) into water anddilute to 1 L. (WarningSodium hydroxide c

21、an cause chemi-cal burns to the skin and eyes. Use of proper safety equipmentis advised.)7.6 A clean organic solvent or hot alkaline solution thatcontains no ammoniacal-type groups or substituents.7.7 Sulfuric Acid Solution (50 mL/L)Slowly add 50 mL ofconcentrated sulfuric acid (H2SO4) into water an

22、d dilute to 1 L.8. Test Media8.1 Slowly add the sodium hydroxide solution to the am-monium chloride solution to give a test solution with a pHvalue appropriate for the intended application (see Annex A1).Maintain the solution at ambient temperature and dilute withDI water up to a volume of 1 L. Chec

23、k the pH value with thepH meter after dilution. Prepare the solution preferably in afume hood in a laboratory using appropriate safe laboratoryprocedures and store it in a closed vessel. Before use, check thepH value again, and adjust if necessary.8.1.1 In the closed test vessel, the ratio of surfac

24、e area oftest solution to air volume of the vessel above the solution shallbe a minimum of 20 cm2/L.8.2 The pickling solution for cleaning test pieces before andafter testing shall be 5 % sulfuric acid. If necessary, forcleaning test pieces after testing, a small amount of hydrogenperoxide solution

25、may be added to the pickling solution (forexample, 20 to 30 mL of hydrogen peroxide solution per litreof pickling solution).9. Test Specimen Preparation9.1 The test specimen size shall be prescribed in thespecification of the product or part being tested. In the eventthat a test specimen size is not

26、 prescribed in a given rod, wire,or tube specification, a full cross section having a minimumlength of 152 mm shall be tested.9.2 The presence of burrs on the test specimen may con-tribute to acceleration of stress corrosion cracking if notremoved before the ammonia vapor test. The burrs shall berem

27、oved by fine file or abrasive paper to facilitate this test.9.3 Degrease the test specimen using the clean organicsolvent or alkaline solution.9.4 After degreasing, clean the test piece in the picklingsolution and immediately thereafter thoroughly rinse it, first incold running water, then in hot wa

28、ter, and finally, completelydry it in a stream of warm air.10. Test Procedure10.1 Allow the dry test piece to reach the exposure tem-perature specified below, and transfer it immediately to theclosed vessel (see 6.2) at the same temperature, and containingthe freshly prepared test solution at the sp

29、ecified pH value (see8.1).10.1.1 Suspend (or place) the test piece such that theammonia vapor has free access to all surfaces, not less than 50mm above the test solution surface.10.1.1.1 When placed on a porcelain support within the testvessel, the region of the test piece within 5 mm of the support

30、shall be disregarded when inspecting for cracks.10.1.1.2 The test piece shall be placed no less than 10 mmfrom the inside walls of the test vessel.10.1.1.3 When more than one test piece is placed in thevessel, the test pieces shall be no less than 10 mm apart.10.2 The volume of the test solution sha

31、ll be at least 200 mLper square decimeter of test piece surface. The exposuretemperature shall be between 20 and 30 C and shall be keptconstant to within 61 C during the test. In case of dispute, theexposure temperature shall be 25 6 1 C.10.3 The exposure time shall be 24 h.10.4 After exposure, remo

32、ve the test piece from the closedvessel and immediately clean it in pickling solution for a fewminutes at ambient temperature (below 40 C), or until thesurfaces of the test piece are sufficiently clean from corrosionproducts to allow observation of possible cracks. After rinsingin water and drying i

33、n warm air, examine the surface of the testpiece for cracks at a magnification of 10 to 15.10.5 Before inspection, deform the test piece slightly bybending or flattening to open up fine cracks to make them moreeasily observable.10.6 Metallographic examination may be used to evaluatethe nature of any

34、 observed cracks.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, seeAnalar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and theUnited St

35、ates Pharmacopeia andNational Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.B858 06 (2018)211. Test Report11.1 The test report shall contain the following information:11.1.1 Sample identification,11.1.2 Reference to the test method used,11.1.3 The pH value used for the solutio

36、n producing theammonia vapor atmosphere,11.1.4 The number of replicate test pieces tested,11.1.5 The test results: cracks or no cracks (as required inthe appropriate product specification),11.1.6 Any other features of the material noted during thedetermination, and11.1.7 The date of the test.12. Pre

37、cision and Bias12.1 No information is presented about either the precisionor bias of this test method for determining susceptibility tostress corrosion cracking in copper alloys since the procedureis directed at a subjective nonquantitative visual interpretationof condition of the specimen and its r

38、elation to an applicableproduct specification.13. Keywords13.1 ammonia test; copper alloys; residual stress; stresscorrosion; stress corrosion crackingANNEX(Mandatory Information)A1. REPRESENTATIVE pH VALUESA1.1 On the basis of the known correlation between thebehavior of test pieces in the ammonia

39、vapor test and thebehavior of copper alloy products under service conditions, thefollowing pH values are considered as being representative ofatmospheres of different corrosiveness and corresponding todifferent safety requirements.A1.1.1 An appropriate risk level (pH value) shall be speci-fied in th

40、e product specification.Corrosiveness of AtmospherepH Value Safety RequirementLow HighLowIndoor atmosphere conditions 8.3 9.5ModerateIndoor atmosphere with risk of formation ofcondensation9.5 10.0Outdoor atmosphere, temperate climate 9.8 10.0HighAtmosphere with ammoniacal pollution, forexample in st

41、ables10.0 10.5APPENDIX(Nonmandatory Information)X1. RATIONALE (COMMENTARY)X1.1 This test method was developed to address the demandfor a test method for determination of the presence of residualstresses in copper alloy products which may lead to stresscorrosion cracking other than the mercurous nitr

42、ate test, TestMethod B154. Research work performed by Mattsson, et al4validates the technical integrity of the test method.X1.2 This test method does not attempt to compare theeffectiveness of the test to other test methods, including themercurous nitrate test, Test Method B154, nor does it attemptt

43、o quantify its relative effectiveness on various copper alloyproducts. These issues must be addressed on a case-by-casebasis, since such products and tests are specific for theirrespective requirements and applications.4Einar Mattsson, Rolf Holm, and Lars Hassel, “Ammonia Test for StressCorrosion of

44、 Copper Alloys.”B858 06 (2018)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof i

45、nfringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this sta

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