GMW14872-2006CyclicCorrosionLaboratoryTest（复合盐雾试验）
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Note:Nothinginthestandardsupersedesapplicablelawsandregulationsunlessspecificexemptionhasbeeenobtained.
Note:IntheeventofconflictbetweentheEnglishanddomesticlanguage,theEnglishlanguageshalltakeprecedence.
1.1Purpose.Thisproceduredescribesanacceleratedlaboratorycorrosiontestmethodtoevaluateassembliesandcomponents.Thetestprocedureprovidesacombinationofcyclicconditions(saltsolution,varioustemperatures,humidity,andambientenvironment)toacceleratemetalliccorrosion.Theprocedureiseffectiveforevaluatingavarietyofcorrosionmechanisms,suchasgeneral,galvanic,crevice,etc.Thetestexposure/conditionscanbeindividuallytailoredtoachieveanydesiredlevelofcorrosionexposure.
Also,synergisticeffectsduetotemperature,mechanicalandelectricalcyclingalongwithotherstressescanbecomprehendedbythistest.SeeDeviationsSection,whichaftertheAppendices,fortypicalmodifications.
1.2Foreword.Thetestmethodiscomprisedof1%（approximate）complexsaltmistapplicationscoupledwithhightemperatureandhighhumidityandhightemperaturedryoff.One(1)testcycleisequalto24h.
AcycleismadeupofthedailyeventsortestinputsillustratedinAppedixA,FigureA1.Acyclenormallyrequiresone(1)daytocomplete.Thetestexposureisdictatedbyatargetedcouponmassloss.AtargetraneforthenumberofcyclesnecessarytomeettherequiredmasslossisprovidedinAppendixA,TableA1.Thecouponmasslossvaluesareusedtoverifythatthecorrectamountofcorrosionhasbeenproducedbythetest.Inadditiontomeetingmasslossrequirements,thetestmustbeconductedsuchthatthenumberofcyclesrequiredtomeetcouponmasslossrequirementsfallswithinthespecifiedrange.
1.3Applicability.Thisisacycliccorrosiontest(refertoAppendixA,FigureA1)usedforvalidationtesting(cosmeticand/orfunctional/generaldurabiliy),developmenttesting,andqualitycontroltesting,forallglobalenvironmentalregions(refertoGMW8738forspecificMethodandapplicableregion).
ThebasicexposuresforcosmeticcorrosionarefoundbelowinexposuresAthroughC.ExposureDisusedforfunctionalassessment(refertoAppendixA,TableA1).Allcorrosionmechanismsareacceleratedatdifferentratesontest.Completingthetestmaynotensurethatacomponentpassesthefunctionalrequirement.Acomprehensivefailuremodeanalysismustbeconductedtoensureallfailuremodesareconsideredandlifeexpectancyismet.
ExposureA:UnderbodyComponents
ExposureB:UnderhoodComponents
ExposureC:ExteriorComponents/Panels,SecondarySurfaces,andInteriorComponents
ExposureD:AllComponents(Functional)
Note:ReferencetheDeviationssectionofthisdocumentforoptionalmodifications.
2References
Note:Onlythelatestapprovedstandardsareapplicableunlessotherwisespecified.
2.1ExternalStandards/Specifications.
ASTMD610ISO8407
ASTMD1193ISO12103-1
ISO6270-2SAEJ2329
2.2GMStandards/Specifications.
GMW8738GMW15357
GMW14700GMW15358
GMW15282GMW15359
GMW15356
2.3AdditionalReferences.
SAE2001-01-0640