【英文标准名称】:StandardTestMethodforConductingCyclicGalvanostaircasePolarization
【原文标准名称】:循环电流梯级极化的标准试验方法
【标准号】:ASTMG100-1989(2010)e1
【标准状态】:现行
【国别】:美国
【发布日期】:1989
【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】:aluminum;corrosion;electrochemicalmeasurement;galvanostaircase;localizedcorrosion;polarization;UNSA93003(Wr.alum.alloy);Alloys;Aluminumalloys--corrosiontesting;Breakdownpotential(Eb);Crevicecorrosion;Cycliccorrosiontesti
【摘要】:Inthistestmethod,susceptibilitytolocalizedcorrosionofaluminumisindicatedbyaprotectionpotential(Eprot)determinedbycyclicgalvanostaircasepolarization(1).Themorenoblethispotential,thelesssusceptibleisthealloytoinitiationoflocalizedcorrosion.Theresultsofthistestmethodarenotintendedtocorrelateinaquantitativemannerwiththerateofpropagationoflocalizedcorrosionthatonemightobserveinservice.Thebreakdown(Eb),andprotectionpotentials(Eprot)determinedbythecyclicGSCPmethodcorrelatewiththeconstantpotentialcorrosiontest(immersion-glassware)resultforaluminum(1,6,8).WhentheappliedpotentialwasmorenegativethantheGSCPEprot,nopitinitiationwasobserved.WhentheappliedpotentialwasmorepositivethantheGSCPEprot,pittingoccurredevenwhentheappliedpotentialwaslessnegativethanEb.SeverecrevicecorrosionoccurredwhentheseparationofEbandEprotwas500mVorgreaterandEprotwaslessthanx2212;400mVVs.SCE(in100ppmNaCl)(1,6,7).Foraluminum,EprotdeterminedbycyclicGSCPagreeswiththerepassivationpotentialdeterminedbythescratchpotentiostaticmethod(1,10).BoththescratchpotentiostaticmethodandtheconstantpotentialtechniquefordeterminationofEprotrequiremuchlongertesttimesandaremoreinvolvedtechniquesthantheGSCPmethod.DeBerryandViebeck(3-5)foundthatthebreakdownpotentials(Eb)(galvanodynamicpolarization,similartoGSCPbutnokineticinformation)hadagoodcorrelationwiththeinhibitionoflocalizedcorrosionof304Lstainlesssteelbysurfaceactivecompounds.Theyattainedaccuracyandprecisionbyavoidingthestronginductioneffectwhichtheyobservedbythepotentiodynamictechnique.Ifthistestmethodisfollowedusingthespecificalloydiscusseditwillprovide(GSCP)measurementsthatwillreproducedatadevelopedatothertimesinotherlaboratories.EbandEprotobtainedarebasedontheresultsfromeightdifferentlaboratoriesthatfollowedthestandardprocedureusingaluminumalloy3003-H14(UNSA93003).EbandEprotareincludedwithstatisticalanalysistoindicatetheacceptablerange.1.1Thistestmethodcoversaprocedureforconductingcyclicgalvanostaircasepolarization(GSCP)todeterminerelativesusceptibilitytolocalizedcorrosion(pittingandcrevicecorrosion)foraluminumalloy3003-H14(UNSA93003)(1).Itmayserveasguideforexaminationofotheralloys(2-5).Thistestmethodalsodescribesaprocedurethatcanbeusedasacheckforone''sexperimentaltechniqueandinstrumentation.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafet......
【中国标准分类号】:A29
【国际标准分类号】:25_220_20
【页数】:4P.;A4
【正文语种】:英语