ASTM G192-2008 用动电位-恒电流-恒电位技术测定耐腐蚀合金潜在缝隙腐蚀的标准试验方法

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【英文标准名称】:StandardTestMethodforDeterminingtheCreviceRepassivationPotentialofCorrosion-ResistantAlloysUsingaPotentiodynamic-Galvanostatic-PotentiostaticTechnique
【原文标准名称】:用动电位-恒电流-恒电位技术测定耐腐蚀合金潜在缝隙腐蚀的标准试验方法
【标准号】:ASTMG192-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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】:G01.11
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:corrosion&x2013;resistantalloys;crevicerepassivationpotential;electrochemicaltest
【摘要】:TheTHEtestmethodisdesignedtoprovidehighlyreproduciblecrevicerepassivationpotentialsforcorrosionx2013;resistantalloys(forexample,Alloy22)inawiderangeofenvironmentsfromnon-aggressivetohighlyaggressive.Inconditionsoflowenvironmentalaggressiveness(suchaslowtemperatureorlowchlorideconcentration),corrosionx2013;resistantalloyssuchasAlloy22willresistcrevicecorrosioninitiationandthecyclicpotentiodynamicpolarizationtest(TestMethodG61)mayfailtopromotecrevicecorrosionmainlybecauseitdrivesthealloyintotranspassivedissolutioninsteadofnucleatingcrevicecorrosion.TheTHEtestmethodprovidesamorecontrolledwayofapplyingtheelectricalchargetothetestelectrode,whichmayinducecrevicecorrosionwithoutmovingitintotranspassivepotentials.Themorenoblethiscrevicecorrosionrepassivationpotential(ER,CREV)value,themoreresistantthealloyistocrevicecorrosioninthetestedelectrolyte.ThisissimilartoothertestmethodstomeasurelocalizedcorrosionresistancesuchasTestMethodG61andTestMethodsG48.Theresultsfromthistestmethodarenotintendedtocorrelateinaquantitativemannerwiththerateofpropagationthatonemightobserveinservicewhenlocalizedcorrosionoccurs.Thistestmethodmaybeusedtorankseveralalloysbyusingthesametestingelectrolyteandtemperature.Itcanalsobeusedtodeterminetheresponseofagivenalloywhentheenvironmentalconditions(suchaselectrolytecompositionandtemperature)change.1.1Thistestmethodcoversaprocedureforconductinganodicpolarizationstudiestodeterminethecrevicerepassivationpotentialforcorrosionx2013;resistantalloys.TheconceptoftherepassivationpotentialissimilartothatoftheprotectionpotentialgiveninReferenceTestMethodG5.1.2Thetestmethodconsistsinapplyingsuccessivelypotentiodynamic,galvanostatic,andpotentiostatictreatmentsfortheinitialformationandafterwardrepassivationofcrevicecorrosion.1.3ThistestmethodisacomplementtoTestMethodG61.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:H25
【国际标准分类号】:77_060
【页数】:10P.;A4
【正文语种】:英语