ASTM G95-2007 管道涂层的阴极剥离试验用标准试验方法(附着电池法)

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【英文标准名称】:StandardTestMethodforCathodicDisbondmentTestofPipelineCoatings(AttachedCellMethod)
【原文标准名称】:管道涂层的阴极剥离试验用标准试验方法(附着电池法)
【标准号】:ASTMG95-2007
【标准状态】:现行
【国别】:
【发布日期】:2007
【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】:D01.48
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:胶粘连接;粘结强度;涂层;材料;非金属;管道;测试
【英文主题词】:anode;attachedcell;cathodic;disbondment;electricalstress;electrolyte;saltbridge
【摘要】:Damagetopipecoatingisalmostunavoidableduringtransportationandconstruction.Breaksorholidaysinpipecoatingsmayexposethepipetopossiblecorrosionsince,afterapipehasbeeninstalledunderground,thesurroundingearthwillbemoisture-bearingandwillconstituteaneffectiveelectrolyte.Appliedcathodicprotectionpotentialsmaycauselooseningofthecoating,beginningatholidayedges.Spontaneousholidaysmayalsobecausedbysuchpotentials.Thistestmethodprovidesacceleratedconditionsforcathodicdisbondmenttooccurandprovidesameasureofresistanceofcoatingstothistypeofaction.Theeffectsofthetestaretobeevaluatedbyphysicalexaminationsandmonitoringthecurrentdrawnbythetestspecimen.Usuallythereisnocorrelationbetweenthetwomethodsofevaluation,butbothmethodsaresignificant.Physicalexaminationconsistsofassessingtheeffectivecontactofthecoatingwiththemetalsurfaceintermsofobserveddifferencesintherelativeadhesivebond.Itisusuallyfoundthatthecathodicallydisbondedareapropogatesfromanareawhereadhesioniszerotoanareawhereadhesionreachestheoriginallevel.Anintermediatezoneofdecreasedadhesionmayalsobepresent.Assumptionsassociatedwithtestresultsinclude:4.3.1Maximumadhesion,orbond,isfoundinthecoatingthatwasnotimmersedinthetestliquid,and4.3.2Decreasedadhesionintheimmersedtestareaistheresultofcathodicdisbondment.Abilitytoresistdisbondmentisadesiredqualityonacomparativebasis,butdisbondmentinthistestmethodisnotnecessarilyanadverseindicationofcoatingperformance.Thevirtueofthistestmethodisthatalldielectric-typecoatingsnowincommonusewilldisbondtosomedegree,thusprovidingameansofcomparingonecoatingtoanother.Thecurrentdensityappearinginthistestmethodismuchgreaterthanthatusuallyrequiredforcathodicprotectioninnaturalenvironments.1.1Thistestmethodcoversacceleratedproceduresforsimultaneouslydeterminingcomparativecharacteristicsofcoatingsystemsappliedtosteeppipeexteriorforthepurposeofpreventingormitigatingcorrosionthatmayoccurinundergroundservicewherethepipewillbeincontactwithnaturalsoilsandwillreceivecathodicprotection.Theyareintendedforusewithsamplesofcoatedpipetakenfromcommercialproductionandareapplicabletosuchsampleswhenthecoatingischaracterizedbyfunctionasanelectricalbarrier.1.2Thistestmethodisintendedtofacilitatetestingofcoatingswherethetestcelliscementedtothesurfaceofthecoatedpipespecimen.ThisisappropriatewhenitisimpracticaltosubmergeorimmersethetestspecimenasrequiredbyTestMethodsG8,G42,orG80.Coatingsampleconfigurationsuchasflatplateandsmalldiameterpipemaybeused,providedthatthetestprocedureremainsunchanged.1.3Thistestmethodallowsoptionsthatmustbeidentifiedinthereport.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A29
【国际标准分类号】:23_040_99
【页数】:4P.;A4
【正文语种】: