ASTM-B499-2009(R2014)-用磁化法测量磁性基底金属材料的非磁化涂层厚度的试验方法

Designation:B499−09(Reapproved2014)EndorsedbyAmericanElectroplaters’SocietyEndorsedbyNationalAssociationofMetalFinishersStandardTestMethodforMeasurementofCoatingThicknessesbytheMagneticMethod:NonmagneticCoatingsonMagneticBasisMetals1ThisstandardisissuedunderthefixeddesignationB499;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodcoverstheuseofmagneticinstrumentsforthenondestructivemeasurementofthethicknessofnon-magneticcoatingsoverferrousorothermagneticbasemetals.Itisintendedtosupplementmanufacturers’instructionsfortheoperationoftheinstrumentsandisnotintendedtoreplacethem.NOTE1—Autocatalyticallydepositednickel-phosphorusalloyscontain-ingmorethan8%phosphorusaresufficientlynonmagnetictobemeasuredbythistestmethod,aslongasthemeasurementismadepriortoanyheattreatment.1.2Theseinstrumentsmeasureeitherthemagneticattrac-tionbetweenamagnetandthebasismetal,asinfluencedbythepresenceofthecoating(categorizedas“magneticpull-off”),orthechangeinmagnetic-fluxdensitywithintheprobe(catego-rizedas“electronic”).Theseinstrumentscannotdistinguishthethicknessofindividuallayers.Theycanonlymeasurethecumulativethicknessofalllayersbeneaththeprobedowntothebasemetal.1.3MeasurementsmadeinaccordancewiththistestmethodwillbeincompliancewiththerequirementsofISOInterna-tionalStandard2178asprintedin1982.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2B530TestMethodforMeasurementofCoatingThicknessesbytheMagneticMethod:ElectrodepositedNickelCoat-ingsonMagneticandNonmagneticSubstrates2.2InternationalStandard:ISO2178Non-MagneticCoatingsonMagneticSubstrate—MeasurementofCoatingThickness—MagneticMethod33.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1accuracy,n—themeasureofthemagnitudeoferrorbetweentheresultofameasurementandthetruethicknessoftheitembeingmeasured.3.1.2adjustment,n—thephysicalactofaligningainstru-ment’sthicknessreadingstomatchthoseofaknownthicknesssample(removalofbias),inordertoimprovetheaccuracyoftheinstrumentonaspecificsurfaceorwithinaspecificportionofitsmeasurementrange.Anadjustmentwillaffecttheoutcomeofsubsequentreadings.3.1.3calibration,n—thehigh-level,controlledanddocu-mentedprocessofobtainingmeasurementsontraceablecali-brationstandardsoverthefulloperatingrangeoftheinstrument,thenmakingthenecessaryinstrumentadjustments(asrequired)tocorrectanyout-of-toleranceconditions.3.1.3.1Discussion—Calibrationofcoatingthicknessinstru-mentsisperformedbytheequipmentmanufacturer,anautho-rizedagent,orbyanauthorized,trainedcalibrationlaboratoryinacontrolledenvironmentusingadocumentedprocess.Theoutcomeofthecalibrationprocessistorestore/realigntheinstrumenttomeet/exceedthemanufacturer’sstatedaccuracy.1ThistestmethodisunderthejurisdictionofASTMCommitteeB08onMetallicandInorganicCoatingsandisthedirectresponsibilityofSubcommitteeB08.10onTestMethods.CurrenteditionapprovedMay1,2014.PublishedMay2014.Originallyapprovedin1969.Lastpreviouseditionapprovedin2009asB499–09.DOI:10.1520/B0499-09R14.2ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,4thFloor,NewYork,NY10036,©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959.UnitedStates13.1.4referencestandard,n—aspecimenofknownthicknessusedtoverifytheaccuracyofacoatingthicknessmeasuringinstrument.3.1.5verificationofaccuracy,n—obtainingmeasurementsonareferencestandardpriortoinstrumentuseforthepurposeofdeterminingtheabilityofthecoatingthicknessinstrumenttoproducereliablevalues,comparedtothecombinedinstrumentmanufacturer’sstatedaccuracyandthestatedaccuracyofthereferencestandard.4.SummaryofTestMethod4.1Magneticpull-offinstrumentsemployanattractionprin-cipleandastationarymagneticfield.Thesemechanicalinstru-mentsmeasuretheforcerequiredtopullapermanentmagnetfromacoatedmagneticmetalsubstrate.Themagneticforceofattractiontothesubstratebeneaththecoatingisopposedbyaspringorcoil.Tensionisappliedtothespring/coiluntilthemagneticattractiontothemagneticsubstrateisovercome.Theinstrumentmustbeplaceddirectlyonthecoatedsurfacetoobtainameasurement.Theforceholdingthepermanentmagnettothemagneticbaseisinverselyproportionaltothethicknessofthecoatinglayer(s)betweenthemagnetandthemagneticbase.Forexample,athincoatingappliedtoaferroussubs