【英文标准名称】:StandardPracticeforUseofMattsson''sSolutionofpH7.2toEvaluatetheStress-CorrosionCrackingSusceptibilityofCopper-ZincAlloys
【原文标准名称】:用pH值为7.2的玛特松(mattsson's)溶液评价铜锌合金的应力腐蚀断裂灵敏性
【标准号】:ASTMG37-1998(2004)
【标准状态】:现行
【国别】:
【发布日期】:1998
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:G01.06
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:锌;腐蚀;金属;试验;评价;工艺;灵敏性;磨损;铜;溶液;耐腐蚀性;使用;合金
【英文主题词】:acceleratedstress-corrosioncrackingtestenvironment;continuousimmersion;copper-ammoniumsulfatesolution;copper-zincalloys
【摘要】:Thistestenvironmentisbelievedtogiveanacceleratedrankingoftherelativeorabsolutedegreeofstress-corrosioncrackingsusceptibilityfordifferentbrasses.Ithasbeenfoundtocorrelatewellwiththecorrespondingservicerankinginenvironmentsthatcausestress-corrosioncrackingwhichisthoughttobeduetothecombinedpresenceoftracesofmoistureandammoniavapor.Theextenttowhichtheacceleratedrankingcorrelateswiththerankingobtainedafterlong-termexposuretoenvironmentscontainingcorrodentsotherthanammoniaisnotatpresentknown.Examplesofsuchenvironmentsmaybeseveremarineatmospheres(Clx2212;),severeindustrialatmospheres(predominantlySO2),andsuper-heatedammonia-freesteam.Itisnotpossibleatpresenttospecifyanyparticulartimetofailure(definedonthebasisofanyparticularfailurecriteria)inpH7.2Mattssonrsquo;solutionthatcorrespondstoadistinctionbetweenacceptableandunacceptablestress-corrosionbehaviorinbrassalloys.Suchparticularcorrelationsmustbedeterminedindividually.Mattssonrsquo;solutionofpH7.2mayalsocausestressindependentgeneralandintergranularcorrosionofbrassestosomeextent.Thisleadstothepossibilityofconfusingstress-corrosionfailureswithmechanicalfailuresinducedbycorrosion-reducednetcrosssections.Thisdangerisparticularlygreatwithsmallcrosssectionspecimens,highappliedstresslevels,longexposureperiodsandstress-corrosionresistantalloys.Carefulmetallographicexaminationisrecommendedforcorrectdiagnosisofthecauseoffailure.Alternatively,unstressedcontrolspecimensmaybeexposedtoevaluatetheextenttowhichstressindependentcorrosiondegradesmechanicalproperties.1.1ThispracticecoversthepreparationanduseofMattsson''ssolutionofpHasanacceleratedstress-corrosioncrackingtestenvironmentforbrasses(copper-zincbasealloys).Thevariables(totheextentthattheseareknownatpresent)thatrequirecontrolaredescribedtogetherwithpossiblemeansforcontrollingandstandardizingthesevariables.1.2Thispracticeisrecommendedonlyforbrasses(copper-zincbasealloys).Theuseofthistestenvironmentisnotrecommendedforothercopperalloyssincetheresultsmaybeerroneous,providingcompletelymisleadingrankings.Thisisparticularlytrueofalloyscontainingaluminumornickelasdeliberatealloyingadditions.1.3Thispracticeisintendedprimarilywherethetestobjectiveistodeterminetherelativestress-corrosioncrackingsusceptibilityofdifferentbrassesunderthesameordifferentstressconditionsortodeterminetheabsolutedegreeofstresscorrosioncrackingsusceptibility,ifany,ofaparticularbrassorbrasscomponentunderoneormorespecificstressconditions.Otherlegitimatetestobjectivesforwhichthistestsolutionmaybeuseddo,ofcourse,exist.Thetensilestressespresentmaybeknownorunknown,appliedorresidual.Thepracticemaybeappliedtowroughtbrassproductsorcomponents,brasscastings,brassweldments,andsoforth,andtoallbrasses.Strictenvironmentaltestconditionsarestipulatedformaximumassurancethatapparentvariationsinstress-corrosionsusceptibilityareattributabletorealvariationsinthematerialbeingtestedorinthetensilestresslevelandnottoenvironmentalvariations.1.4Thispracticerelatessolelytothepreparationandcontrolofthetestenvironment.Noattemptismadetorecommendsurfacepreparationorfinish,orboth,asthismayvarywiththetestobjectives.Similarly,noattemptismadetorecommendparticularstress-corrosiontestspecimenconfigurationsormethodsofapplyingthestress.TestspecimenconfigurationsthatmaybeusedarereferencedinPracticeG30andSTP42......
【中国标准分类号】:H25
【国际标准分类号】:77_060;77_120_30
【页数】:3P.;A4
【正文语种】: