汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用

汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用2024/3/24汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用MicroalloySteelApplications-?KevinHulseyIllustration,Inc.(2005)SheetsteelsforouterbodyandstructuralcomponentsEngineComponents:CrankshaftsConnectingrodsSuspensioncomponentsTransmissioncomponents???FutureApplications???Gears,axles,shafts,hubs汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用UltraLightSteelAutoSuspension,AISI(2001),Etc.7%AutomotiveMaterials汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Example:TrendsinEngineDesignC.Lema?tre,AISTBarConf.,WinterPark,Colorado(2006)ReduceSizekW/LNewenvironmentallegislation–continuedreductionsinallowableemissionsDiesel:IncreasedinjectionpressuresGasoline:Increaseduseofturboand/orcompressorsEuropeanData汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用LighterweightpowerplantsforimprovedfueleconomyRequirehigherstrengthmaterialsMicroalloyedbarsteelsforcrankshaftsIncreasedstiffness(comparedtocastiron)BetterfatigueresistanceReducedcomponentweightAllowsmallerandlighterflywheelsandclutchsystemsAISIReport–2004Example:TrendsinEngineDesign汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Historical:UseofMicroalloyedForgingSteelsforAutomotiveComponentsInitialapplicationsinEurope–1980’sBasedondirect-cooledferrite-pearlitesteelsGrowthinuseintheUS–1990’sFerrite-pearlitesteelsNon-traditionalbainiticsteelswithretainedausteniteWithimprovedprocessingcontrolandunderstandingofmicroalloyingfundamentals,usecontinuestoexpand.汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用RequirementsforNewMicroalloyedBarandForgingSteels

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

ProductBenefitsMoreefficientvehicledesignsHighertorque-capacitycomponentsHigheroperatingstressesSafervehiclesImprovedcrashworthiness汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用PresentationOverview? OpportunitiesforuseofMicroalloyedSteelsinAutomobilesReducemanufacturingcostsBalancepropertiesandperformanceTailor

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

PresentationbasedonSelectedExamplesAutomotiveSpringsForgingsforGearsThermomechanicalProcessingTransmissionComponents汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用MicrostructuralClassesofMicroalloyedSteelsFerrite-PearliteSteels–DirectCooledStrengthenedby:PearlitevolumefractionFerritegrainsizeandsubstructurePrecipitationstrengtheningofferrite (e.g.VandNb)HeatTreatedSteelsThroughhardened(martensiticorbainitic)InductionhardenedsurfacesSurfacemodifiedandheattreatedCarburized汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Direct-CooledForgingSteelsKasparetal.,MicroalloyingForgingSteels,TMS,1996TIMETIMEConventionalQuenchandTemperDirect-cooledafterforgingBenefitofDirect-Cooling:ReducedprocessingtimeandcostRequirements:Equipmentcapableofcontrolledcooling汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels? SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用MicroalloyPrecipitateSolubility? Microalloyelementsinmetals:AssolidsolutionalloyadditionsInprecipitates Atgrainboundaries WithingrainsPrecipitatesformbetweensolidsolutionelementsandinterstitialsofCorN

Microalloy

Interstitials

Typical

Elements

Precipitates Nb C NbC NbN V N VC VN Ti TiC TiN Al AlNSpecificprecipitatesthatformdependoncompositionandtemperature汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用SolubilityOverview? Applyequilibriumthermodynamicstopredictstateofmicroalloyelementsinalloy–drivingforceforprecipitateformationcontrolledbysolubilityReactionsofInterest:

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

yM+zX=MyXz

4V+3C=V4C3ReactionRate: ks=Equilibriumconstant

ks

isreferredtoasthesolubilityproductandisequaltotheratioofactivities:

汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用SolubilityOverview? Temperaturedependenceofsolubilityproduct,ks,describedbyanArrheniusequation;i.e.Byconventionksgivenby:ExamplesolubilitydiagramforNbC

汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Example:NbCSolubilityDiagramAssume: T=1100oC [Nb]=0.1wtpct [C]=0.2wtpct

Solubilitydatafrom:Narita,TransISIJ(1975)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用EffectsofCompositionandTemperatureExample:NbCSolubilityDiagramSolubilitydatafrom:Narita,TransISIJ(1975)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Carbide/NitrideSolubilityIncreasedStabilityLowersolubilityproduct= IncreasedprecipitatestabilityExamples:At1200oCTiNismorestablethanNbC,VNAtalltemperaturesVChasloweststability,e.g.VCeasilydissolvesathighertemperatures汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用From:Matlock,Krauss,andSpeer,Microalloying‘05ImportanceofUnderstandingSolubilityTemperaturerangesinwhichcarbides,nitrides,andcarbonitridesformanddissolvedeterminesuitabilityforagivenmicroalloyingdesign.Forexample:TiN,stableattemperaturesinexcessof1200oC,usedforaustenitegrainsizecontrolathighforgingtemperaturesandduringhigh-temperaturecarburizingVN(andcarbonitrides)dissolveatlowaustenitizingtemperaturesVisavailableforfine-scaleprecipitationstrengtheningoncoolingafterforgingNbC(andTiC)dissolveandprecipitateattemperaturesintermediatetoTiNandVPrecipitatespreventausteniterecrystallizationduringfinishhotrolling–resultsinfineferritegrainsizes.汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Carbide/NitrideSolubilityCompareAusteniteandFerrite汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用AlloyingandProcessControlSolubilitycontrolsdrivingforceforprecipitation,volumefraction,etc.ApproachtousesolubilityproductsSpecifyalloycontent EvaluatesolubilitiesofconstituentsDeterminewhichprecipitatesform/dissolveattemperature/compositionofinterestPredictaustenitecompositionandprecipitatevolumefractionsDesignprocessmethodologyApproachwillbeillustratedwithNb-modifiedgearsteelsforhightemperaturecarburizing.汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels? SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用? Considergraingrowthcontrol

Duringhotworking DuringheattreatingGraingrowthlimitedbysecondphaseparticles

R=stablegrainsize

r=particleradius

f=volumefractionparticlesFinergrainsize=decreaserorincreasefSizeandvolumefractioncontrolledbyalloyingandprocessing

Iftoosmall–particlesredissolve Iftoolarge–particlesareineffectiveTypesofgraingrowthNormalgraingrowthAbnormalgraingrowthParticleEffectsonGrainGrowth汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Steel:ControlledRolledwith0.02NbTime:60minutesHeatingRate:145°C/minNGG=NormalAGG=AbnormalIAGG=InitialAbnormalGrainGrowthTerminologyK.AlOgab,PhD,ASPPRC,CSM(2004)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ParticleEffectsonGrainGrowth[1] MovingGrainBoundaryApproachesParticleParticleGB[2] ParticleDecreasesGrainBoundaryAreaGB[3]ParticleRetardsBoundaryMovement汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ParticleEffectsonGrainGrowthFrom:Krauss,Steels,ASM,(2005)PlainCarbonSteelsNormalgraingrowth(withoutparticles)SteelwithParticlesGraingrowthslowedbyparticles汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ParticleEffectsonGrainGrowthFrom:Krauss,Steels,ASM,(2005)PlainCarbonSteelsNormalgraingrowth(withoutparticles)SteelwithParticlesGraingrowthslowedbyparticlesParticledissolutionathighertemperaturesresultsinabnormalgraingrowth汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ParticleEffectsonGrainGrowthFrom:AlOgab,PhD,ASPPRC,ColoradoSchoolofMines(2004)ExampleLightOpticalMicrographsAbnormalGrainGrowthNormalGrainGrowth100mm100mm100mm汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainGrowthControl–Ti,V,Al,NbFrom:Krauss,Steels,ASM,(2005)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用From:Krauss,Steels,ASM,(2005)GrainGrowthControl–ImportanceofNb汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainGrowthControl–ImportanceofNbFrom:Krauss,Steels,ASM,(2005)andK.AlOgab,PhD,ASPPRC,CSM(2004)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用From:Krauss,Steels,ASM,(2005)Summary:GrainGrowthControlMicroalloyingelementsproduceparticlesthatsuppressgraingrowthParticledissolutionleadstoabnormalgraingrowthandsteelswithlargeaveragegrainsizesParticlesize,volumefraction,anddistributioncontrolledbymicroalloyadditionsandtemperatureTiandNbeffectiveincreatingparticlesthatsuppressgraingrowth汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FundamentalsofMicrostructureControlandStrengtheningMechanismsinMicroalloyedBarSteels? SolubilityConsiderationsMicrostructuralControlandGrainGrowthduringProcessingStrengtheningandTougheningMechanisms汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用StrengtheningMechanisms? GrainSizeRefinement

Increasestrength Increasefatigueresistance Increasetoughness RefinestransformedmicrostructuresPrecipitationStrengtheningTransformationStrengthening汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Hall-PetchEquationGrainboundaryblocksslipbandStressconcentratedatheadofblockedslipbandStrengthening:GrainSizeEffectsBarrettetal.(1973)andGladman(1997)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainSizeRefinementFrom:Krauss,Steels,ASM,(2005)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainSizeRefinementAusteniterefinementalsomodifiesmartensitepacketsizeinquenchedandtemperedsteels.From:Krauss,Steels,ASM,(2005)Martensitepacketsizev.austenitegrainsizeYieldstrengthdependsonpacketsize汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FatigueEnduranceLimits:CarburizedGearSteelsCornelissenetal.,ASM(2000)Modified4320and8620GearSteelsFinerAusteniteGrainSize汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FatigueEnduranceLimits:CarburizedGearSteelsCornelissenetal.,ASM(2000)Modified4320and8620GearSteelsFinerAusteniteGrainSizeRefinedPriorAusteniteGrainSizeLeadsDirectlytoImprovedFatigueResistance汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainSizeEffectsonToughnessCharpyV-NotchDataFinegrainsizelowerstransitiontemperatureFinegrainsresist cleavagefractureFerriticSteelsFinerFerriteGrainSizeFrom:Hertzberg(1989)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用PrecipitationStrengtheningStrengthincreaseswithsmallerparticlesizesorgreatervolumefractionsλPinnedDislocation0.1C-0.04Nb(wtpct)Steel(FromGladman,1985)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用D.Ponge,(2005)CombinedEffects:GrainRefinementandPrecipitation汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Direct-CooledMicroalloyedBarSteelsSawadaetal.,ISS-AIME,(1994)Directcoolafterforging–ferrite-pearliteor“non-traditionalbainite”microstructuresHighcarboncriticalforstrengthMicroalloying

precipitationhardeningStrengthIncreasetoughnessdecrease汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Direct-CooledMicroalloyedBarSteelsS.Thompson,ASPPRC,(2006)Pearlite+InterphasePrecipitation汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ImportanceofInterlamellarSpacing? PearlitestrengthandtoughnessdependoninterlamellarspacingFrom:Gladman,inMicroalloyingForgingSteels,TMS,1996S=trueinterlamellarspacingt=pearliticcarbidethickness汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Summary:StrengtheningMechanisms? ContributionsofdifferentstrengtheningmechanismsareadditiveManyequationsavailableintheliteraturetosummarizeproperties(e.g.seeGladman’stext)OpportunitiesexisttodesignmaterialswithspecificmechanicalpropertiesFrom:Gladman,inMicroalloyingForgingSteels,TMS,1996汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ThermomechanicalProcessingofMicroalloyedBarSteels汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用TMPControlofMicrostructuresExampleReference:BoydandZhao,inNewDevelopmentsinLongandForgedProducts,AIST,(2006)PurposeofStudy:

Compareforgingschedulesdesignedtocontrolausteniterecrystallizationwithalloycontentinmodified1541alloysVariables:

Forginghistory(temperature),coolingrate,microalloyadditionsBoydandZhao,AIST,(2006)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BoydandZhao,AIST,(2006)Warmforging:Designedtofinishinferrite-pearliteregionForgingSchedulesAppliedtoNb/V/TiSteelsGoal:Producerefinedferriteandpearlitecolonies+precipitationstrengtheningDeformationinAustenite:Designedtoproducenon-recrystallizedaustenite汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BoydandZhao,AIST,(2006)WarmForged1541withNbSEMMicrographsResult:

successfullyproducedrefinedmicrostructuresStrengthenedalsobydislocationsubstructureinferrite汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用D.Ponge,(2005)ThermomechancialProcessingAlsoEnhancesPrecipitation汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BoydandZhao,AIST,(2006)EffectofTMPonMechanicalPropertiesWarmForged:1541+NbForgedtoproducenon-recrystallizedausteniteConventionalForging1541+Ti/V1541+Nb汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BoydandZhao,AIST,(2006)Summary–ThermomechanicalProcessingMicrostructureswithrefinedferriteandpearlitecanbesuccessfullyproducedtoincreasebothstrengthandtoughnessPrecipitatesresultingfromNbadditionssuccessfullysuppressedgraingrowthtoyieldthesuperiorproperties.Thermomechanicalprocessingofmicroalloyedbarsteelsoffersopportunitiesforpropertydevelopmentinnewsteels.汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用ExampleAutomotiveSprings汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Example:AutomotiveSprings? DesignRequirements:

Higherstrength Improvedfatigueresistance Improvedtoughness LighterweightHistorically,springsteelsbasedonSAE5160andmorerecently,SAE9259Recently,microalloyedsteels,basedonNb+Vhaveledtoimprovedmaterials汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用SpringSteelCompositionsNewMicroalloyedGrade:LowerC,withSi,Nb,andVUseThermomechanicalProcessingtocontrolgrainsizeWith(maxvalues)0.02P;0.021S;0.012Ni(inwtpct)M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用SpringSteelProcessingHotRolledFormedHeatTreated Austenitize~940oCTEMShowedNbPrecipitatesforControlofAusteniteGrainSize

M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用FrontSuspensionCoilSpringinNorthAmericanMinivan:ImprovedwithMicroalloyedSteelM.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Summary–SpringSteelDevelopmentControlledthermomechanicalprocessingiscriticalinordertobeabletoutilizebenefitsofmicroalloyingtocontrolandrefinefinalmicrostructureFinalpropertiesbenefitfromcontributionsofbothNbandVinalloys.Developmentofimprovedmicroalloyspringsteelswillcontinue.M.Head,etal.,StelcoInc.,SAE(2006)andGDIS,汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用Example:VacuumCarburizedGears汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BendingFatigueInGears汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用TrendsforAutomotiveGearSteelsCarburizeathigherT:930oC1050oCShorterheattreatcycle=$$UsealternatetechnologiesVacuumorlow-pressureplasmacarburizingHigherTgascarburizingDesignalloystorespondtomodifiedthermalhistories

usemicroalloyadditionsImprovematerialpropertiesFatigueresistanceBendingfatigueContactfatigue汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用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

汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainSizeand“Vacuum”CarburizingAdvancedCarburizing:

PlasmaandVacuummayoperateathighertemperatures=shortercycletimes,but……..GrainGrowthFromDavidsonetal.2001汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用AusteniteGrainSize–ImportancetoFatigueofCarburizedSteelsFineGrainSize=IncreasedEnduranceLimitCornelissenetal.(2000)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用TrendsforAutomotiveGearSteelsMethodstorefineaustenitegrainsizesincarburizedgearsteelReheataftercarburizeandquench--RefinebytransformationcyclingRequiresextraheattreatcycle=$$UtilizemicroalloyprecipitatestosuppressgraingrowthAlloydesignsbasedonsolubilityandprocesstemperatureconsiderations汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用LaboratoryBendingFatigueSampleProductionGearSet:RingandPinonBendingFatigueofCarburizedSteelsASPPRC,Golden,CO(2006)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用BendingFatigueFailureMechanismsinCarburizedSteelsGasCarburized4820SteelMatlocketal.ABM,S?oPaulo,Brazil(2004)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用GrainRefinement:TiAdditionsTitanium+NitrogenTitaniumNitridePrecipitatesFromDavidsonetal.2001汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用200mmSimulatedCarburizing8620@927oC(noTi)PlasmaCarburizing8620@1093oCPlasmaCarburizing@1093oC8620Modified:Ti+N200mm50mmd=15mmd=123mmd=57mmFromDavidsonetal.(2001)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用TiadditionsonlyproducegrainrefinementTooptimizealloytoresistgraingrowth,useboth

NbandTitofurthersuppressaustenitegraingrowthSummary:TiAdditions汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用PrecipitateControlofAusteniteGrainSizeDuringCarburizingMicroalloyDesign:TiTiNthenNb

NbCtofurthersuppressaustenitegraingrowthAlloys:Base:8620with0.03Ti0.02Nb,0.06Nb,0.11NbLabmeltedHeats(Timken)–hotorcontrolledrolledAlOgabetal.ISIJ(2007)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用AddTitoprecipitateallNasTiNReviewBasisforAlloyDesignAlOgabetal.ISIJ(2007)汽車零部件用微合金非調(diào)質(zhì)鋼的開發(fā)及應用DesignofNbAlloys00.10.20.3C(wt.%)

00.040.080.12Nb(wt.%)

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