ASTM-D2247-15在100%相对湿度下涂层的耐水性试验

Designation:D2247−15StandardPracticeforTestingWaterResistanceofCoatingsin100%RelativeHumidity1ThisstandardisissuedunderthefixeddesignationD2247;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thispracticecoversthebasicprinciplesandoperatingproceduresfortestingwaterresistanceofcoatingsbyexposingcoatedspecimensinanatmospheremaintainedat100%relativehumiditysothatcondensationformsonallsurfacesoftestspecimens.1.2Thispracticeusesthetechniqueofcreatingaslighttemperaturedifferentialwithintheexposureareatoformcondensationonthecoatedspecimens.Asthewarmersatu-ratedairpassesthecoolerspecimens,waterisdepositedontothespecimensintheformofcondensation.1.3Thispracticeplacestheentirespecimenintheexposureareaallowingcondensationtoformonallsurfaces.Thismakesthispracticesuitableforflatpanelsaswellaslargeor3Dobjects.Thispracticediffersfromothermethodswherecon-densationisonlyformedonthefrontcoatingsurface,whilethebacksurfaceisoutsidetheexposurearea.Othertestsmayalsodepositwaterdropletsonthesurfacebutwherethesourceisnotfromcondensation(forexample,waterspray).NOTE1—AlternativepracticesfortestingthewaterresistanceofcoatingsincludePracticesD870,D1735,andD4585.1.4Thispracticeislimitedtothemethodsofobtaining,measuring,andcontrollingtheconditionsandproceduresoftestsconductedin100%relativehumidity.Itdoesnotspecifyspecimenpreparation,orevaluationofresults.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D609PracticeforPreparationofCold-RolledSteelPanelsforTestingPaint,Varnish,ConversionCoatings,andRelatedCoatingProductsD610PracticeforEvaluatingDegreeofRustingonPaintedSteelSurfacesD714TestMethodforEvaluatingDegreeofBlisteringofPaintsD823PracticesforProducingFilmsofUniformThicknessofPaint,Varnish,andRelatedProductsonTestPanelsD870PracticeforTestingWaterResistanceofCoatingsUsingWaterImmersionD1193SpecificationforReagentWaterD1654TestMethodforEvaluationofPaintedorCoatedSpecimensSubjectedtoCorrosiveEnvironmentsD1730PracticesforPreparationofAluminumandAluminum-AlloySurfacesforPaintingD1735PracticeforTestingWaterResistanceofCoatingsUsingWaterFogApparatusD2616TestMethodforEvaluationofVisualColorDiffer-enceWithaGrayScaleD3359TestMethodsforMeasuringAdhesionbyTapeTestD3363TestMethodforFilmHardnessbyPencilTestD4541TestMethodforPull-OffStrengthofCoatingsUsingPortableAdhesionTestersD4585PracticeforTestingWaterResistanceofCoatingsUsingControlledCondensation3.SummaryofPractice3.1Coatedspecimensareplacedinanenclosedchambercontainingaheated,saturatedmixtureofairandwatervapor.Thetemperatureofthechamberisusuallymaintainedat38°C(100°F).At100%relativehumidity(RH),averysmalltemperaturedifferencebetweenthespecimenandthesurround-ingvaporcausestheformationofcondensationonthespeci-mens.Theexposureconditionisvariedbyselectingthe1ThispracticeisunderthejurisdictionofASTMCommitteeD01onPaintandRelatedCoatings,Materials,andApplicationsandisthedirectresponsibilityofSubcommitteeD01.27onAcceleratedTesting.CurrenteditionapprovedDec.1,2015.PublishedDecember2015.Originallyapprovedin1966.Lastpreviouseditionapprovedin2011asD2247–11.DOI:10.1520/D2247-15.2ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.*ASummaryofChangessectionappearsattheendofthisstandardCopyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959.UnitedStates1durationofthetest.Waterpermeatesthecoatingatratesthataredependentuponthecharacteristicsofthecoating.Anyeffectssuchascolorchange,blistering,lossofadhesion,softening,orembrittlementareobservedandreported.4.SignificanceandUse4.1Watercancausethedegradationofcoatings,soknowl-edgeofhowacoatingresistswaterishelpfulforassessinghowitwillperforminactualservice.Failureintestsat100%relativehumiditymaybecausedbyanumberoffactorsincludingadeficiencyinthecoatingitself,contaminationofthesubstrate,orinadequatesurfacepreparation.Thispracticeisthereforeusefulforevaluatingcoatingsaloneorcompletecoatingsystems.4.2Testsat100%relativehumidityareusedforspecifica-tionacceptance,qualitycontrol,andresearchanddevelopmentforcoatingsandsubstratetreatments.Sometestsareusedforapassorfaildeterminationatanarbitrarytime.Acoatingsystemisconsideredtopassifthereisnoevidenceofwater-relatedfailureafteraperiodoftime.Othertestsareusedtomonitordegreeoffailureasafunctionofexposuretime.4.2.1Arbitrarypass/fail