ASTM E 45-2005

ASTME45-2005Designation:E45–05StandardTestMethodsforDeterminingtheInclusionContentofSteel1ThisstandardisissuedunderthefixeddesignationE45;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thesetestmethodscoveranumberofrecognizedproceduresfordeterminingthenonmetallicinclusioncontentofwroughtsteel.Macroscopicmethodsincludemacroetch,fracture,step-down,andmagneticparticletests.Microscopicmethodsincludefivegenerallyacceptedsystemsofexamina-tion.Inthesemicroscopicmethods,inclusionsareassignedtoacategorybasedonsimilaritiesinmorphology,andnotnecessarilyontheirchemicalidentity.Metallographictech-niquesthatallowsimpledifferentiationbetweenmorphologi-callysimilarinclusionsarebrieflydiscussed.Whilethemeth-odsareprimarilyintendedforratinginclusions,constituentssuchascarbides,nitrides,carbonitrides,borides,andinterme-tallicphasesmayberatedusingsomeofthemicroscopicmethods.Insomecases,alloysotherthansteelsmayberatedusingoneormoreofthesemethods;themethodswillbedescribedintermsoftheiruseonsteels.1.2ThispracticecoversprocedurestoperformJK-typeinclusionratingsusingautomaticimageanalysisinaccordancewithmicroscopicmethodsAandD.1.3Dependingonthetypeofsteelandthepropertiesrequired,eitheramacroscopicoramicroscopicmethodfordeterminingtheinclusioncontent,orcombinationsofthetwomethods,maybefoundmostsatisfactory.1.4Thesetestmethodsdealonlywithrecommendedtestmethodsandnothinginthemshouldbeconstruedasdefiningorestablishinglimitsofacceptabilityforanygradeofsteel.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.Valuesinparenthesesareconversionsandareap-proximate.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D96TestMethodforWaterandSedimentinCrudeOilbyCentrifugeMethod(FieldProcedure)E3GuideforPreparationofMetallographicSpecimensE7TerminologyRelatingtoMetallographyE381MethodofMacroetchTestingSteelBars,Billets,Blooms,andForgingsE709GuideforMagneticParticleExaminationE768PracticeforPreparingandEvaluatingSpecimensforAutomaticInclusionAssessmentofSteelE1245PracticeforDeterminingInclusionorSecond-PhaseConstituentContentofMetalsbyAutomaticImageAnaly-sisE1444PracticeforMagneticParticleExaminationE1951GuideforCalibratingReticlesandLightMicro-scopeMagnifications2.2SAEStandards:3J422,RecommendedPracticeforDeterminationofInclu-sionsinSteel2.3AerospaceMaterialSpecifications:3AMS2300,PremiumAircraft-QualitySteelCleanliness:MagneticParticleInspectionProcedureAMS2301,AircraftQualitySteelCleanliness:MagneticParticleInspectionProcedureAMS2303,AircraftQualitySteelCleanliness:MartensiticCorrosion-ResistantSteelsMagneticParticleInspectionProcedureAMS2304,SpecialAircraft-QualitySteelCleanliness:MagneticParticleInspectionProcedure2.4ISOStandards:4ISO3763,WroughtSteels—MacroscopicMethodsforAs-sessingtheContentofNonmetallicInclusions1ThesetestmethodsareunderthejurisdictionofASTMCommitteeE04onMetallographyandisthedirectresponsibilityofSubcommitteeE04.09onInclu-sions.CurrenteditionapprovedNov.1,2005.PublishedDecember2005.Originallyapprovedin1942.Lastpreviouseditionapprovedin2002asE45–97(2002).2ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.3AvailablefromSocietyofAutomotiveEngineers(SAE),400CommonwealthDr.,Warrendale,PA15096-0001.4AvailablefromAmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,4thFloor,NewYork,NY10036.Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.CopyrightASTMInternational,100BarrHarborDrive,WestConshohocken,Pennsylvania19428,USA.DistributedunderASTMlicenseagreementbyChinaNationalInstituteofStandardization(CNIS)-Tel:861058811350授权用户：1，打印日期：2006-6-1，订单号：ISO4967,Steel—DeterminationofContentofNonmetallicInclusions—MicrographicMethodsUsingStandardDia-grams2.5ASTMAdjuncts:InclusionsinSteelPlatesI-randII5FourPhotomicrographsofLowCarbonSteel63.Terminology3.1Definitions:3.1.1Fordefinitionsoftermsusedinthispractice,seeTerminologyE7.3.1.2TerminologyE7includestheterminclusioncount;sincesomemethodsofthesetestmethodsinvolvelengthmeasurementsorconversionstonumericalrepresentationsoflengthsorcounts,orboth,theterminclusionratingispreferred.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1aspectratio—thelength-to-widthratioofamicro-structuralfeature.3.2.2discontinuousstringer—threeormoreTypeBorCinclusionsalignedinaplaneparalleltothehotworkingaxisandoffsetbynomorethan15µm,withaseparationoflessthan40µm(0.0016in.)betweenanytwonearestneighborinclu-sions.3.2.3inclusiontypes—fordefinitionsofsulfide-,alumina-,andsilicate-typeinclusions,seeTerminologyE7.Globularoxide,insomemethodsreferstoisolated,relativelynonde-formedinclusionswithanaspectrationotinexcessof2:1.Inothermethods,oxidesaredividedintodeformableandnonde-formabletypes.3.2.4JKinclusionrating—amethodofmeasuringnonme-tallicinclusionsbasedontheSwedishJernkontoretprocedures;MethodsAandDofthesetestmethodsaretheprincipalJKratingmethods,andMethodEalsousestheJKratingcharts.3.2.5stringer—anindividualinclusionthatishighlyelon-gatedinthedeformationdirectionorthreeormoreTypeBorCinclusionsalignedinaplaneparalleltothehotworkingaxisandoffsetbynomorethan15µm,withaseparationoflessthan40µm(0.0016in.)betweenanytwonearestneighborinclu-sions.3.2.6thresholdsetting—isolationofarangeofgraylevelvaluesexhibitedbyoneconstituentinthemicroscopefield.3.2.7worst-fieldrating—aratinginwhichthespecimenisratedforeachtypeofinclusionbyassigningthevalueforthehighestseverityratingobservedofthatinclusiontypeany-whereonthespecimensurface.4.SignificanceandUse4.1Thesetestmethodscoverfourmacroscopicandfivemicroscopictestmethods(manualandimageanalysis)fordescribingtheinclusioncontentofsteelandproceduresforexpressingtestresults.4.2Inclusionsarecharacterizedbysize,shape,concentra-tion,anddistributionratherthanchemicalcomposition.Al-thoughcompositionsarenotidentified,Microscopicmethodsplaceinclusionsintooneofseveralcomposition-relatedcat-egories(sulfides,oxides,andsilicates—thelastasatypeofoxide).Paragraph12.2.1describesametallographictechniquetofacilitateinclusiondiscrimination.Onlythoseinclusionspresentatthetestsurfacecanbedetected.4.3Themacroscopictestmethodsevaluatelargersurfaceareasthanmicroscopictestmethodsandbecauseexaminationisvisualoratlowmagnifications,thesemethodsarebestsuitedfordetectinglargerinclusions.Macroscopicmethodsarenotsuitablefordetectinginclusionssmallerthanabout0.40mm(1⁄64in.)inlengthandthemethodsdonotdiscriminateinclusionsbytype.4.4Themicroscopictestmethodsareemployedtocharac-terizeinclusionsthatformasaresultofdeoxidationorduetolimitedsolubilityinsolidsteel(indigenousinclusions).Theseinclusionsarecharacterizedbymorphologicaltype,thatis,bysize,shape,concentration,anddistribution,butnotspecificallybycomposition.Themicroscopicmethodsarenotintendedforassessingthecontentofexogenousinclusions(thosefromentrappedslagorrefractories).4.5Becausetheinclusionpopulationwithinagivenlotofsteelvarieswithposition,thelotmustbestatisticallysampledinordertoassessitsinclusioncontent.Thedegreeofsamplingmustbeadequateforthelotsizeanditsspecificcharacteristics.Materialswithverylowinclusioncontentsmaybemoreaccuratelyratedbyautomaticimageanalysis,whichpermitsmoreprecisemicroscopicratings.4.6Resultsofmacroscopicandmicroscopictestmethodsmaybeusedtoqualifymaterialforshipment,butthesetestmethodsdonotprovideguidelinesforacceptanceorrejectionpurposes.Qualificationcriteriaforassessingthedatadevel-opedbythesemethodscanbefoundinASTMproductstandardsormaybedescribedbypurchaser-produceragree-ments.Byagreementsbetweenproducerandpurchaser,thispracticemaybemodifiedtocountonlycertaininclusiontypesandthicknesses,oronlythoseinclusionsaboveacertainseveritylevel,orboth.Also,byagreement,qualitativeprac-ticesmaybeusedwhereonlythehighestseverityratingsforeachinclusiontypeandthicknessaredefinedorthenumberoffieldscontainingthesehighestseverityratingsaretabulated.4.7Thesetestmethodsareintendedforuseonwroughtmetallicstructures.Whileaminimumlevelofdeformationisnotspecified,thetestmethodsarenotsuitableforuseoncaststructuresoronlightlyworkedstructures.4.8Guidelinesareprovidedtorateinclusionsinsteelstreatedwithrareearthadditionsorcalcium-bearingcom-pounds.Whensuchsteelsareevaluated,thetestreportshoulddescribethenatureoftheinclusionsratedaccordingtoeachinclusioncategory(A,B,C,D).4.9InadditiontothePracticeE45JKratings,basic(suchasusedinPracticeE1245)stereologicalmeasurements(forexample,thevolumefractionofsulfidesandoxides,thenumberofsulfidesoroxidespersquaremillimeter,thespacingbetweeninclusions,andsoforth)maybeseparatelydeter-minedandaddedtothetestreport,ifdesiredforadditionalinformation.Thispractice,however,doesnotaddressthemeasurementofsuchparameters.5AvailablefromASTMHeadquarters.OrderADJE004502.6AvailablefromASTMHeadquarters.OrderADJE004501.授权用户：1，打印日期：2006-6-1，订单号：MACROSCOPICMETHODS5.MacroscopicalTestMethodsOverview5.1Summary:5.1.1Macro-etchTest—Themacro-etchtestisusedtoindicateinclusioncontentanddistribution,usuallyinthecrosssectionortransversetothedirectionofrollingorforging.Insomeinstances,longitudinalsectionsarealsoexamined.Testsarepreparedbycuttingandmachiningasectionthroughthedesiredareaandetchingwithasuitablereagent.Asolutionofoneparthydrochloricacidandonepartwateratatemperatureof71to82°C(160to180°F)iswidelyused.Asthenameofthistestimplies,theetchedsurfaceisexaminedvisuallyoratlowmagnificationforinclusions.DetailsofthistestareincludedinMethodE381.Thenatureofquestionableindica-tionsshouldbeverifiedbymicroscopicexaminationorothermeansofinspection.5.1.1.1Sulfidesarerevealedaspitswhenthestandardetchantdescribedin5.1.1isused.5.1.1.2Onlylargeoxidesarerevealedbythistestmethod.5.1.2FractureTest—Thefracturetestisusedtodeterminethepresenceandlocationofinclusionsasshownonthefractureofhardenedslicesapproximately9to13mm(3⁄8to1⁄2in.)thick.Thistestisusedmostlyforsteelswhereitispossibletoobtainahardnessofapproximately60HRCandafracturegrainsizeof7orfiner.Testspecimensshouldnothaveexcessiveexternalindentationsornotchesthatguidethefracture.Itisdesirablethatfracturebeinthelongitudinaldirectionapproximatelyacrossthecenteroftheslice.Thefracturedsurfacesareexaminedvisuallyandatmagnificationsuptoapproximatelytendiameters,andthelengthanddistri-butionofinclusionsisnoted.Heattinting,orblueing,willincreasevisibilityofoxidestringers.ISO3763providesachartmethodforfracturesurfaceinclusionratings.Insomein-stances,indicationsassmallas0.40mm(1⁄64in.)inlengtharerecorded.5.1.3Step-DownMethod—Thestep-downtestmethodisusedtodeterminethepresenceofinclusionsonmachinedsurfacesofrolledorforgedsteel.Thetestsampleismachinedtospecifieddiametersbelowthesurfaceandsurveyedforinclusionsundergoodilluminationwiththeunaidedeyeorwithlowmagnification.Insomeinstances,testsamplesaremachinedtosmallerdiametersforfurtherexaminationaftertheoriginaldiametersareinspected.Thistestisessentiallyusedtodeterminethepresenceofinclusions3mm(1⁄8in.)inlengthandlonger.5.1.4MagneticParticleMethod—Themagneticparticlemethodisavariationofthestep-downmethodforferromag-neticmaterialsinwhichthetestsampleismachined,magne-tized,andmagneticpowderisapplied.Discontinuitiesassmallas0.40mm(1⁄64in.)inlengthcreatemagneticleakagefieldsthatattractthemagneticpowder,therebyoutliningtheinclu-sion.SeePracticeE1444andGuideE709onmagneticparticleexaminationsformoredetailsoftheprocedure.RefertoAerospaceMaterialsSpecificationsAMS2300,AMS2301,AMS2303,andAMS2304.5.2Advantages:5.2.1Thesetestmethodsfacilitatetheexaminationofspeci-menswithlargesurfaceareas.Thelargerinclusionsinsteel,whicharethemainconcerninmostcases,arenotuniformlydistributedandthespacesbetweenthemarerelativelylarge,sothatthechancesofrevealingthemarebetterwhenlargerspecimensareexamined.5.2.2Specimensformacroscopicexaminationmaybequicklypreparedbymachiningandgrinding.Ahighlypolishedsurfaceisnotnecessary.Themacroscopicmethodsaresuffi-cientlysensitivetorevealthelargerinclusions.5.3Disadvantages:5.3.1Thesetestmethodsdonotdistinguishamongthedifferentinclusionshapes.5.3.2Theyarenotsuitableforthedetectionofsmallglobularinclusionsorofchainsofveryfineelongatedinclu-sions.5.3.3Themagneticparticlemethodcanleadtoincorrectinterpretationofmicrostructuralfeaturessuchasstreaksofretainedaustenite,microsegregation,orcarbidesincertainalloys;thisisparticularlylikelyifhighmagnetizationcurrentsareemployed.MICROSCOPICMETHODS6.MicroscopicTestMethodsOverview6.1Microscopicmethodsareusedtocharacterizethesize,distribution,number,andtypeofinclusionsonapolishedspecimensurface.Thismaybedonebyexaminingthespeci-menwithalightmicroscopeandreportingthetypesofinclusionsencountered,accompaniedbyafewrepresentativephotomicrographs.Thismethod,however,doesnotlenditselftoauniformreportingstyle.Therefore,standardreferencechartsdepictingaseriesoftypicalinclusionconfigurations(size,type,andnumber)werecreatedfordirectcomparisonwiththemicroscopicfieldofview.Amethodusingimageanalysistomakethesecomparisonshasalsobeendeveloped.6.2Variousreferencechartsofthisnaturehavebeende-visedsuchastheJKchart7andtheSAEchartfoundinSAERecommendedPracticeJ422oftheSAEHandbook.ThemicroscopicmethodsinTestMethodsE45userefinedcom-parisonchartsbasedonthesecharts.MethodA(WorstFields),MethodD(LowInclusionContent)andMethodE(SAMRating)usechartsbasedontheJKchartwhileMethodC(OxidesandSilicates)usestheSAEchart.ISOStandard4967alsousestheJKchart.6.3Nochartcanrepresentallofthevarioustypesandformsofinclusions.Theuseofanychartisthuslimitedtodetermin-ingthecontentofthemostcommontypesofinclusions,anditmustbekeptinmindthatsuchadeterminationisnotacompletemetallographicstudyofinclusions.6.4Analternatetocomparison(chart)methodssuchasMethodsA,CandD8maybefoundinMethodB.MethodB(Length)isusedtodetermineinclusioncontentbasedonlength.Onlyinclusions0.127mm(0.005in.)orlongerarerecordedregardlessoftheirtype.Fromthismethodonemay7TheJKchartderivesitsnamefromitssponsorsJernkontoret,theSwedishIronmastersAssociation.8Notethatwhilethesemethodsarecalledcomparisonchartmethods,theprocedureusedmayalsoconsistoflengthmeasurementsorcountsofinclusions,orboth.授权用户：1，打印日期：2006-6-1，订单号：obtaindatasuchaslengthofthelongestinclusionandaverageinclusionlength.Inaddition,photomicrographsmayalsobetakentocharacterizethebackgroundinclusionsthatwerenotlongenoughtomeasure.6.5Theadvantagesofthemicroscopicmethodsare:6.5.1Inclusionscanbecharacterizedastotheirsize,type,andnumber.6.5.2Extremelysmallinclusionscanberevealed.6.6Adisadvantageofthemicroscopicmethodsisthatindividualratingfieldsareverysmall(0.50mm2).Thislimitsthepracticalsizeofthespecimen,asitwouldsimplytakeaprohibitivenumberoffieldstocharacterizealargespecimen.Theresultobtainedbyamicroscopiccharacterizationoftheinclusionsinalargesectionisgovernedbychanceiflocalvariationsintheinclusiondistributionaresubstantial.Theenduseoftheproductdeterminestheimportanceofthemicro-scopicresults.Experienceininterpretingtheseresultsisnecessaryinordernottoexaggeratetheimportanceofsmallinclusionsinsomeapplications.6.7Indeterminingtheinclusioncontent,itisimportanttorealizethat,whatevermethodisused,theresultactuallyappliesonlytotheareasofthespecimensthatwereexamined.Forpracticalreasons,suchspecimensarerelativelysmallcomparedwiththetotalamountofsteelrepresentedbythem.Fortheinclusiondeterminationtohaveanyvalue,adequatesamplingisjustasnecessaryasapropermethodoftesting.6.8Steeloftendiffersininclusioncontentnotonlyfromheattoheat,butalsofromingottoingotinthesameheatandevenindifferentportionsofthesameingot.Itisessentialthattheunitlotofsteel,theinclusioncontentofwhichistobedetermined,shallnotbelargerthanoneheat.Sufficientsamplesshouldbeselectedtorepresentthelotadequately.Theexactsamplingprocedureshouldbeincorporatedintheindi-vidualproductrequirementsorspecifications.Forsemifinishedproducts,thespecimensshouldbeselectedafterthematerialhasbeensufficientlycroppedandsuitablediscardsmade.Ifthelocationsofthedifferentingotsandportionsofingotsintheheatcannotbeidentifiedinthelotbeingtested,randomsamplingshouldinvolveagreaternumberoftestspecimensforanequivalentweightofsteel.Avaluefortheinclusioncontentofanisolatedpieceofsteel,evenifaccuratelydetermined,shouldnotbeexpectedtorepresenttheinclusioncontentofthewholeheat.6.9Thesizeandshapeofthewroughtsteelproducttestedhasamarkedinfluenceonthesizeandshapeoftheinclusions.Duringreductionfromthecastshapebyrollingorforging,theinclusionsareelongatedandbrokenupaccordingtothedegreeofreductionofthesteelcrosssection.Inreportingresultsofinclusiondeterminations,therefore,thesize,shape,andmethodofmanufactureofthesteelfromwhichthespecimenswerecutmustbestated.Incomparingtheinclusioncontentofdifferentsteels,theymustallberolledorforgedasnearlyaspossibletothesamesizeandshape,andfromcastsectionsofaboutthesamesize.Specimenscutlengthwiseorparalleltothedirectionofrollingorforgingshallbeused.6.10Itmaybeconvenient,inordertoobtainmorereadilycomparableresults,toforgecouponsfromlargerbillets.Theseforgedsectionsmaythenbesampledinthesamewayasrolledsections.Exercisecare,however,tocropspecimensofsuffi-cientlengthfromthebilletsforforging;otherwise,thereisdangeroftheshear-draggedendsbeingincorporatedinthespecimens.Suchdistortedmaterialwillgiveafalseresultintheinclusiondetermination.Toavoidthis,itishelpfultosawtheendsofthebilletlengthforforgingandtotakethespecimenfromthemiddleoftheforgedlength.6.11Severalofthemethodsdescribedinthesetestmethodsrequirethataspecificareaofthepreparedsurfaceofthespecimenissurveyed,andallthesignificantinclusionsob-servedberecordedandexpressedintheresults.Thereportedresultforeachspecimenexaminedis,therefore,amoreaccuraterepresentationoftheinclusioncontentthanaphoto-micrographordiagram.AdisadvantageoftheWorstFieldapproachisthatnosuchdistributionofinclusionratingsisobtained.6.12Tomakecomparisonspossiblebetweendifferentheatsanddifferentpartsofheats,theresultsshallbeexpressedinsuchamannerthatanaveragefortheinclusioncontentofthedifferentspecimensintheheatcanbeobtained.Whenthelengthsoftheinclusionsaremeasured,thesimplestnumberisthatfortheaggregatelengthofalltheinclusionsperareaexamined;however,itmaybedesirablenotmerelytoaddthelengthsbutalsotoweighttheinclusionsaccordingtotheirindividuallengths.Thelengthofthelargestinclusionfoundandthetotalnumberofinclusionsmayalsobeexpressed.7.Sampling7.1Toobtainareasonableestimateofinclusionvariationswithinalot,atleastsixlocations,chosentobeasrepresenta-tiveofthelotaspossible,shouldbeexamined.Inthiscontext,alotshallbedefinedasaunitofmaterialprocessedatonetimeandsubjectedtosimilarprocessingvariables.Innocaseshouldmorethanoneheatbeinthesamelot.Forexampleifalotconsistsofoneheat,samplinglocationsmightbeintheproductobtainedfromthetopandbottomofthefirst,middle,andlastusableingotsinthepouringsequence.Forstrandcastorbottompourprocessing,asimilarsamplingplanperheatshouldbeinvoked.7.2Forcasesinwhichadefinitelocationwithinaheat,ingot,orotherunitlotisunknown,statisticalrandomsamplingwithagreaternumberofspecimensshouldbeemployed.7.3Ratingsobtainedwillvarywiththeamountofreductionoftheproduct.Formaterialsacceptanceorforcomparisonamongheats,caremustbetakentosampleatthecorrectstageofprocessing.8.TestSpecimenGeometry8.1Theminimumpolishedsurfaceareaofaspecimenforthemicroscopicdeterminationofinclusioncontentis160mm2(0.25in.2).Itisrecommendedthatasignificantlylargeareashouldbeobtainedsothatthemeasurementsmaybemadewithinthedefinedareaawayfromtheedgesofthesample.Thepolishedsurfacemustbeparalleltothelongitudinalaxisoftheproduct.Inaddition,forflat-rolledproducts,thesectionshallalsobeperpendiculartotherollingplane;forroundsandtubularshapes,thesectionshallbeintheradialdirection.Inallcases,thepolishedsurfaceshallbeparalleltothehot-working授权用户：1，打印日期：2006-6-1，订单号：axis.Studieshavedemonstratedthatinclusionlengthmeasure-mentsaresigni