汽车零部件用微合金非调质钢的开发及应用

汽车零部件用微合金非调质钢的开发及应用2024/3/24汽车零部件用微合金非调质钢的开发及应用MicroalloySteelApplications-©KevinHulseyIllustration,Inc.(2005)SheetsteelsforouterbodyandstructuralcomponentsEngineComponents:CrankshaftsConnectingrodsSuspensioncomponentsTransmissioncomponents???FutureApplications???Gears,axles,shafts,hubs汽车零部件用微合金非调质钢的开发及应用UltraLightSteelAutoSuspension,AISI(2001),Etc.7%AutomotiveMaterials汽车零部件用微合金非调质钢的开发及应用Example:TrendsinEngineDesignC.Lemaître,AISTBarConf.,WinterPark,Colorado(2006)ReduceSizekW/LNewenvironmentallegislation–continuedreductionsinallowableemissionsDiesel:IncreasedinjectionpressuresGasoline:Increaseduseofturboand/orcompressorsEuropeanData汽车零部件用微合金非调质钢的开发及应用LighterweightpowerplantsforimprovedfueleconomyRequirehigherstrengthmaterialsMicroalloyedbarsteelsforcrankshaftsIncreasedstiffness(comparedtocastiron)BetterfatigueresistanceReducedcomponentweightAllowsmallerandlighterflywheelsandclutchsystemsAISIReport–2004Example:TrendsinEngineDesign汽车零部件用微合金非调质钢的开发及应用Historical:UseofMicroalloyedForgingSteelsforAutomotiveComponentsInitialapplicationsinEurope–1980’sBasedondirect-cooledferrite-pearlitesteelsGrowthinuseintheUS–1990’sFerrite-pearlitesteelsNon-traditionalbainiticsteelswithretainedausteniteWithimprovedprocessingcontrolandunderstandingofmicroalloyingfundamentals,usecontinuestoexpand.汽车零部件用微合金非调质钢的开发及应用RequirementsforNewMicroalloyedBarandForgingSteels

Alloying,ProcessingandProductDevelopmentsHigherStrength…with…ExcellentMechanicalPropertiesFormability,Toughness,FatigueResistance,Machinability……..

ProductBenefitsMoreefficientvehicledesignsHighertorque-capacitycomponentsHigheroperatingstressesSafervehiclesImprovedcrashworthiness汽车零部件用微合金非调质钢的开发及应用PresentationOverview• OpportunitiesforuseofMicroalloyedSteelsinAutomobilesReducemanufacturingcostsBalancepropertiesandperformanceTailor

materialsforspecificapplicationElementsofinterestTi,Nb,V,N,C,…Al…andtheirT-dependentsolubilities

PresentationbasedonSelectedExamplesAutomotiveSpringsForgingsforGearsThermomechanicalProcessingTransmissionComponents汽车零部件用微合金非调质钢的开发及应用MicrostructuralClassesofMicroalloyedSteelsFerrite-PearliteSteels–DirectCooledStrengthenedby:PearlitevolumefractionFerritegrainsizeandsubstructurePrecipitationstrengtheningofferrite (e.g.VandNb)HeatTreatedSteelsThroughhardened(martensiticorbainitic)InductionhardenedsurfacesSurfacemodifiedandheattreatedCarburized汽车零部件用微合金非调质钢的开发及应用Direct-CooledForgingSteelsKasparetal.,MicroalloyingForgingSteels,TMS,1996TIMETIMEConventionalQuenchandTemperDirect-cooledafterforgingBenefitofDirect-Cooling:ReducedprocessingtimeandcostRequirements:Equipmentcapableofcontrolledcooling汽车零部件用微合金非调质钢的开发及应用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels• SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽车零部件用微合金非调质钢的开发及应用MicroalloyPrecipitateSolubility• Microalloyelementsinmetals:AssolidsolutionalloyadditionsInprecipitates Atgrainboundaries WithingrainsPrecipitatesformbetweensolidsolutionelementsandinterstitialsofCorN

Microalloy

Interstitials

Typical

Elements

Precipitates Nb C NbC NbN V N VC VN Ti TiC TiN Al AlNSpecificprecipitatesthatformdependoncompositionandtemperature汽车零部件用微合金非调质钢的开发及应用SolubilityOverview• Applyequilibriumthermodynamicstopredictstateofmicroalloyelementsinalloy–drivingforceforprecipitateformationcontrolledbysolubilityReactionsofInterest:

M+X=MX Example: Nb+C=NbC

yM+zX=MyXz

4V+3C=V4C3ReactionRate: ks=Equilibriumconstant

ks

isreferredtoasthesolubilityproductandisequaltotheratioofactivities:

汽车零部件用微合金非调质钢的开发及应用SolubilityOverview• Temperaturedependenceofsolubilityproduct,ks,describedbyanArrheniusequation;i.e.Byconventionksgivenby:ExamplesolubilitydiagramforNbC

汽车零部件用微合金非调质钢的开发及应用Example:NbCSolubilityDiagramAssume: T=1100oC [Nb]=0.1wtpct [C]=0.2wtpct

Solubilitydatafrom:Narita,TransISIJ(1975)汽车零部件用微合金非调质钢的开发及应用EffectsofCompositionandTemperatureExample:NbCSolubilityDiagramSolubilitydatafrom:Narita,TransISIJ(1975)汽车零部件用微合金非调质钢的开发及应用Carbide/NitrideSolubilityIncreasedStabilityLowersolubilityproduct= IncreasedprecipitatestabilityExamples:At1200oCTiNismorestablethanNbC,VNAtalltemperaturesVChasloweststability,e.g.VCeasilydissolvesathighertemperatures汽车零部件用微合金非调质钢的开发及应用From:Matlock,Krauss,andSpeer,Microalloying‘05ImportanceofUnderstandingSolubilityTemperaturerangesinwhichcarbides,nitrides,andcarbonitridesformanddissolvedeterminesuitabilityforagivenmicroalloyingdesign.Forexample:TiN,stableattemperaturesinexcessof1200oC,usedforaustenitegrainsizecontrolathighforgingtemperaturesandduringhigh-temperaturecarburizingVN(andcarbonitrides)dissolveatlowaustenitizingtemperaturesVisavailableforfine-scaleprecipitationstrengtheningoncoolingafterforgingNbC(andTiC)dissolveandprecipitateattemperaturesintermediatetoTiNandVPrecipitatespreventausteniterecrystallizationduringfinishhotrolling–resultsinfineferritegrainsizes.汽车零部件用微合金非调质钢的开发及应用Carbide/NitrideSolubilityCompareAusteniteandFerrite汽车零部件用微合金非调质钢的开发及应用AlloyingandProcessControlSolubilitycontrolsdrivingforceforprecipitation,volumefraction,etc.ApproachtousesolubilityproductsSpecifyalloycontent EvaluatesolubilitiesofconstituentsDeterminewhichprecipitatesform/dissolveattemperature/compositionofinterestPredictaustenitecompositionandprecipitatevolumefractionsDesignprocessmethodologyApproachwillbeillustratedwithNb-modifiedgearsteelsforhightemperaturecarburizing.汽车零部件用微合金非调质钢的开发及应用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels• SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽车零部件用微合金非调质钢的开发及应用• Considergraingrowthcontrol

Duringhotworking DuringheattreatingGraingrowthlimitedbysecondphaseparticles

R=stablegrainsize

r=particleradius

f=volumefractionparticlesFinergrainsize=decreaserorincreasefSizeandvolumefractioncontrolledbyalloyingandprocessing

Iftoosmall–particlesredissolve Iftoolarge–particlesareineffectiveTypesofgraingrowthNormalgraingrowthAbnormalgraingrowthParticleEffectsonGrainGrowth汽车零部件用微合金非调质钢的开发及应用Steel:ControlledRolledwith0.02NbTime:60minutesHeatingRate:145°C/minNGG=NormalAGG=AbnormalIAGG=InitialAbnormalGrainGrowthTerminologyK.AlOgab,PhD,ASPPRC,CSM(2004)汽车零部件用微合金非调质钢的开发及应用ParticleEffectsonGrainGrowth[1] MovingGrainBoundaryApproachesParticleParticleGB[2] ParticleDecreasesGrainBoundaryAreaGB[3]ParticleRetardsBoundaryMovement汽车零部件用微合金非调质钢的开发及应用ParticleEffectsonGrainGrowthFrom:Krauss,Steels,ASM,(2005)PlainCarbonSteelsNormalgraingrowth(withoutparticles)SteelwithParticlesGraingrowthslowedbyparticles汽车零部件用微合金非调质钢的开发及应用ParticleEffectsonGrainGrowthFrom:Krauss,Steels,ASM,(2005)PlainCarbonSteelsNormalgraingrowth(withoutparticles)SteelwithParticlesGraingrowthslowedbyparticlesParticledissolutionathighertemperaturesresultsinabnormalgraingrowth汽车零部件用微合金非调质钢的开发及应用ParticleEffectsonGrainGrowthFrom:AlOgab,PhD,ASPPRC,ColoradoSchoolofMines(2004)ExampleLightOpticalMicrographsAbnormalGrainGrowthNormalGrainGrowth100mm100mm100mm汽车零部件用微合金非调质钢的开发及应用GrainGrowthControl–Ti,V,Al,NbFrom:Krauss,Steels,ASM,(2005)汽车零部件用微合金非调质钢的开发及应用From:Krauss,Steels,ASM,(2005)GrainGrowthControl–ImportanceofNb汽车零部件用微合金非调质钢的开发及应用GrainGrowthControl–ImportanceofNbFrom:Krauss,Steels,ASM,(2005)andK.AlOgab,PhD,ASPPRC,CSM(2004)汽车零部件用微合金非调质钢的开发及应用From:Krauss,Steels,ASM,(2005)Summary:GrainGrowthControlMicroalloyingelementsproduceparticlesthatsuppressgraingrowthParticledissolutionleadstoabnormalgraingrowthandsteelswithlargeaveragegrainsizesParticlesize,volumefraction,anddistributioncontrolledbymicroalloyadditionsandtemperatureTiandNbeffectiveincreatingparticlesthatsuppressgraingrowth汽车零部件用微合金非调质钢的开发及应用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels• SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽车零部件用微合金非调质钢的开发及应用StrengtheningMechanisms• GrainSizeRefinement

Increasestrength Increasefatigueresistance Increasetoughness RefinestransformedmicrostructuresPrecipitationStrengtheningTransformationStrengthening汽车零部件用微合金非调质钢的开发及应用Hall-PetchEquationGrainboundaryblocksslipbandStressconcentratedatheadofblockedslipbandStrengthening:GrainSizeEffectsBarrettetal.(1973)andGladman(1997)汽车零部件用微合金非调质钢的开发及应用GrainSizeRefinementFrom:Krauss,Steels,ASM,(2005)汽车零部件用微合金非调质钢的开发及应用GrainSizeRefinementAusteniterefinementalsomodifiesmartensitepacketsizeinquenchedandtemperedsteels.From:Krauss,Steels,ASM,(2005)Martensitepacketsizev.austenitegrainsizeYieldstrengthdependsonpacketsize汽车零部件用微合金非调质钢的开发及应用FatigueEnduranceLimits:CarburizedGearSteelsCornelissenetal.,ASM(2000)Modified4320and8620GearSteelsFinerAusteniteGrainSize汽车零部件用微合金非调质钢的开发及应用FatigueEnduranceLimits:CarburizedGearSteelsCornelissenetal.,ASM(2000)Modified4320and8620GearSteelsFinerAusteniteGrainSizeRefinedPriorAusteniteGrainSizeLeadsDirectlytoImprovedFatigueResistance汽车零部件用微合金非调质钢的开发及应用GrainSizeEffectsonToughnessCharpyV-NotchDataFinegrainsizelowerstransitiontemperatureFinegrainsresist cleavagefractureFerriticSteelsFinerFerriteGrainSizeFrom:Hertzberg(1989)汽车零部件用微合金非调质钢的开发及应用PrecipitationStrengtheningStrengthincreaseswithsmallerparticlesizesorgreatervolumefractionsλPinnedDislocation0.1C-0.04Nb(wtpct)Steel(FromGladman,1985)汽车零部件用微合金非调质钢的开发及应用D.Ponge,(2005)CombinedEffects:GrainRefinementandPrecipitation汽车零部件用微合金非调质钢的开发及应用Direct-CooledMicroalloyedBarSteelsSawadaetal.,ISS-AIME,(1994)Directcoolafterforging–ferrite-pearliteor“non-traditionalbainite”microstructuresHighcarboncriticalforstrengthMicroalloying

precipitationhardeningStrengthIncreasetoughnessdecrease汽车零部件用微合金非调质钢的开发及应用Direct-CooledMicroalloyedBarSteelsS.Thompson,ASPPRC,(2006)Pearlite+InterphasePrecipitation汽车零部件用微合金非调质钢的开发及应用ImportanceofInterlamellarSpacing• PearlitestrengthandtoughnessdependoninterlamellarspacingFrom:Gladman,inMicroalloyingForgingSteels,TMS,1996S=trueinterlamellarspacingt=pearliticcarbidethickness汽车零部件用微合金非调质钢的开发及应用Summary:StrengtheningMechanisms• ContributionsofdifferentstrengtheningmechanismsareadditiveManyequationsavailableintheliteraturetosummarizeproperties(e.g.seeGladman’stext)OpportunitiesexisttodesignmaterialswithspecificmechanicalpropertiesFrom:Gladman,inMicroalloyingForgingSteels,TMS,1996汽车零部件用微合金非调质钢的开发及应用ThermomechanicalProcessingofMicroalloyedBarSteels汽车零部件用微合金非调质钢的开发及应用TMPControlofMicrostructuresExampleReference:BoydandZhao,inNewDevelopmentsinLongandForgedProducts,AIST,(2006)PurposeofStudy:

Compareforgingschedulesdesignedtocontrolausteniterecrystallizationwithalloycontentinmodified1541alloysVariables:

Forginghistory(temperature),coolingrate,microalloyadditionsBoydandZhao,AIST,(2006)汽车零部件用微合金非调质钢的开发及应用BoydandZhao,AIST,(2006)Warmforging:Designedtofinishinferrite-pearliteregionForgingSchedulesAppliedtoNb/V/TiSteelsGoal:Producerefinedferriteandpearlitecolonies+precipitationstrengtheningDeformationinAustenite:Designedtoproducenon-recrystallizedaustenite汽车零部件用微合金非调质钢的开发及应用BoydandZhao,AIST,(2006)WarmForged1541withNbSEMMicrographsResult:

successfullyproducedrefinedmicrostructuresStrengthenedalsobydislocationsubstructureinferrite汽车零部件用微合金非调质钢的开发及应用D.Ponge,(2005)ThermomechancialProcessingAlsoEnhancesPrecipitation汽车零部件用微合金非调质钢的开发及应用BoydandZhao,AIST,(2006)EffectofTMPonMechanicalPropertiesWarmForged:1541+NbForgedtoproducenon-recrystallizedausteniteConventionalForging1541+Ti/V1541+Nb汽车零部件用微合金非调质钢的开发及应用BoydandZhao,AIST,(2006)Summary–ThermomechanicalProcessingMicrostructureswithrefinedferriteandpearlitecanbesuccessfullyproducedtoincreasebothstrengthandtoughnessPrecipitatesresultingfromNbadditionssuccessfullysuppressedgraingrowthtoyieldthesuperiorproperties.Thermomechanicalprocessingofmicroalloyedbarsteelsoffersopportunitiesforpropertydevelopmentinnewsteels.汽车零部件用微合金非调质钢的开发及应用ExampleAutomotiveSprings汽车零部件用微合金非调质钢的开发及应用Example:AutomotiveSprings• DesignRequirements:

Higherstrength Improvedfatigueresistance Improvedtoughness LighterweightHistorically,springsteelsbasedonSAE5160andmorerecently,SAE9259Recently,microalloyedsteels,basedonNb+Vhaveledtoimprovedmaterials汽车零部件用微合金非调质钢的开发及应用M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽车零部件用微合金非调质钢的开发及应用SpringSteelCompositionsNewMicroalloyedGrade:LowerC,withSi,Nb,andVUseThermomechanicalProcessingtocontrolgrainsizeWith(maxvalues)0.02P;0.021S;0.012Ni(inwtpct)M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽车零部件用微合金非调质钢的开发及应用SpringSteelProcessingHotRolledFormedHeatTreated Austenitize~940oCTEMShowedNbPrecipitatesforControlofAusteniteGrainSize

M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽车零部件用微合金非调质钢的开发及应用FrontSuspensionCoilSpringinNorthAmericanMinivan:ImprovedwithMicroalloyedSteelM.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽车零部件用微合金非调质钢的开发及应用Summary–SpringSteelDevelopmentControlledthermomechanicalprocessingiscriticalinordertobeabletoutilizebenefitsofmicroalloyingtocontrolandrefinefinalmicrostructureFinalpropertiesbenefitfromcontributionsofbothNbandVinalloys.Developmentofimprovedmicroalloyspringsteelswillcontinue.M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽车零部件用微合金非调质钢的开发及应用Example:VacuumCarburizedGears汽车零部件用微合金非调质钢的开发及应用BendingFatigueInGears汽车零部件用微合金非调质钢的开发及应用TrendsforAutomotiveGearSteelsCarburizeathigherT:930oC1050oCShorterheattreatcycle=$$UsealternatetechnologiesVacuumorlow-pressureplasmacarburizingHigherTgascarburizingDesignalloystorespondtomodifiedthermalhistories

usemicroalloyadditionsImprovematerialpropertiesFatigueresistanceBendingfatigueContactfatigue汽车零部件用微合金非调质钢的开发及应用ExampleTimeSavingwith“Vacuum”CarburizingKlinkenbergandJansto,AIST,(2006)Temperature

VacuumCarburizingTime

CaseDepth=1.5mm

17CrNiMo6

930oC

980oC

1030oC

Loading

hr

0.25

0.25

0.25

Heating

hr

1.5

1.75

2

CarburizationandDiffusion

hr

8.5

5

3

CoolingtoQuenchTemperature

hr

0.75

1

1.25

Quenchingandunloading

hr

0.5

0.5

0.5

Overall

hr

11.5

8.5

7

hr

3

4.5

ReductionofTime

%

~25

~40

汽车零部件用微合金非调质钢的开发及应用GrainSizeand“Vacuum”CarburizingAdvancedCarburizing:

PlasmaandVacuummayoperateathighertemperatures=shortercycletimes,but……..GrainGrowthFromDavidsonetal.2001汽车零部件用微合金非调质钢的开发及应用AusteniteGrainSize–ImportancetoFatigueofCarburizedSteelsFineGrainSize=IncreasedEnduranceLimitCornelissenetal.(2000)汽车零部件用微合金非调质钢的开发及应用TrendsforAutomotiveGearSteelsMethodstorefineaustenitegrainsizesincarburizedgearsteelReheataftercarburizeandquench--RefinebytransformationcyclingRequiresextraheattreatcycle=$$UtilizemicroalloyprecipitatestosuppressgraingrowthAlloydesignsbasedonsolubilityandprocesstemperatureconsiderations汽车零部件用微合金非调质钢的开发及应用LaboratoryBendingFatigueSampleProductionGearSet:RingandPinonBendingFatigueofCarburizedSteelsASPPRC,Golden,CO(2006)汽车零部件用微合金非调质钢的开发及应用BendingFatigueFailureMechanismsinCarburizedSteelsGasCarburized4820SteelMatlocketal.ABM,SãoPaulo,Brazil(2004)汽车零部件用微合金非调质钢的开发及应用GrainRefinement:TiAdditionsTitanium+NitrogenTitaniumNitridePrecipitatesFromDavidsonetal.2001汽车零部件用微合金非调质钢的开发及应用200mmSimulatedCarburizing8620@927oC(noTi)PlasmaCarburizing8620@1093oCPlasmaCarburizing@1093oC8620Modified:Ti+N200mm50mmd=15mmd=123mmd=57mmFromDavidsonetal.(2001)汽车零部件用微合金非调质钢的开发及应用TiadditionsonlyproducegrainrefinementTooptimizealloytoresistgraingrowth,useboth

NbandTitofurthersuppressaustenitegraingrowthSummary:TiAdditions汽车零部件用微合金非调质钢的开发及应用PrecipitateControlofAusteniteGrainSizeDuringCarburizingMicroalloyDesign:TiTiNthenNb

NbCtofurthersuppressaustenitegraingrowthAlloys:Base:8620with0.03Ti0.02Nb,0.06Nb,0.11NbLabmeltedHeats(Timken)–hotorcontrolledrolledAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用AddTitoprecipitateallNasTiNReviewBasisforAlloyDesignAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用DesignofNbAlloys00.10.20.3C(wt.%)

00.040.080.12Nb(wt.%)

850110012001300oCWithNasTiN,EvaluateNbCsolubilityAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用Effectofcarbonincreaseduringcarburizingfor0.1and0.3NballoyadditionsReviewBasisforAlloyDesignAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用SAE8620steelwith0.03TiReviewBasisforAlloyDesignAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用PredictionsofdissolvedNbcontentandNbCcontentsasafunctionofcarburizingtemperatureReviewBasisforAlloyDesignTi-modifiedSAE8620Steelwith0.06NbwtpctAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用SolubilitiesatfinishingrollingfinishingtemperaturesHotRolled:Finishat1100oCControlledRolled:Finishat850oCSolubilityConsiderationspredictshigherprecipitatevolumefractionincontrolledrolledmaterialImportanceofThermomechanicalProcessingTi-modifiedSAE8620Steelwith0.06NbwtpctAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用500nmHR0.06NbSteelCR0.06NbSteelImportanceofThermomechanicalProcessingTi-modifiedSAE8620Steel0.06NbwtpctAlOgabetal.ISIJ(2007)汽车零部件用微合金非调质钢的开发及应用100mmNb-Free–60min.HotRolled0.02Nb–240min.InfluenceofNbAdditions:At950oCK.AlOgab,PhD,ASPPRC,CSM(2004)汽车零部件用微合金非调质钢的开发及应用PseudoCarburizingMicrostructures:@950oCBaseAlloy(T)HR0.02Nb6090240360minutes100mmK.AlOgab,PhD,ASPPRC,CSM(2004)汽车零部件用微合金非调质钢的开发及应用PseudoCarburizingResults:GrainGrowthHotRolledControlRolledTi-onlyNbIncreasedNbK.AlOgab,PhD,ASPPRC,CSM(2004)汽车零部件用微合金非调质钢的开发及应用FatiguePerformanceofNb-ModifiedCarburizedGearSteelsFatigueTestatRoomTemperatureUtilizemodifiedBruggerSampleVacuumCarburizedat1050oCFrequency=30HzBasealloy=SAE8620Ti-modifiedSAE8620steelWith0.8Mn,0.6Cr,0.43Ni,0.2Mo(wtpct)R.Thompsonetal.,ASPPRC,CSMSAE(2007)汽车零部件用微合金非调质钢的开发及应用0.06Nb0.1Nb0.02Nb100mm100mm100mmR.