热压成形技术对汽车高强度钢性能影响--毕业论文外文翻译.doc

InfluenceofHotPressFormingTechniquesonPropertiesofVehicleHighStrengthSteelsAbstract:Basedonthecombinationofmaterialsscienceandmechanicalengineering,hotpressformingprocessofthevehiclehighstrengthsteelswasanalyzed.Thehotformingprocessinclud-ed:heatingalloysrapidlytoaustenitemicrostructures,stampingandcoolingtimely,maintainingpressureandquenching.Theresultsshowedthatmostofaustenitemicrostructurewaschangedintouniformmartensitebythehotpressformingwhilethesampleswereheatedat900。Candquenched.Theoptimaltensilestrengthandyieldstrengthwereupto1530MPaand1000MPa,respectively,andtheshapedeformationreachedabout23%.Andspringbackdefectdidnothapp-eninthesamples.Keywords:highstrengthsteel;lightweight;hotforming;martensiteAsaneffectiveeconomicalenergymeasure,thelightweightdevelopmentdirectionofautomo-bilehasbecomeoneofthemostimportantresearchsubjectsintheautomotiveindustry.Therearethreemajorwaystoachieveautomobilelightweight:optimizingvehicleframesandstruc-tures;makingvehiclebodyorframeofnewandalternativematerialstoreducethevehiclemass(Thehighandultrahighstrengthsteelcanbeusedasalternativematerialsbecauseofitsthinnerthickness);adoptingadvancedmanufacturingtechniquesforthesakeofautomobilelightwei-ght,suchasthickness-gradienthighstrengthsteel(HSS)ormetalbasedcompoundplatesbycon-tinuouspressingorhotpressforming[1].AlthoughHSShasbeenappliedinsomedomestictopgradevehicles,thekeyproducingtechnologieshavealwaysbeendominatedbyforeigncompan-ies,suchasAcelorCompany,soastoraisetheproductcostobviously.Bydomesticself-designedhotpressformingtechniquesandwater-coolingmould,theautomobileHSScanbeproducedtosubstituteforeignvehicleparts.Ingeneral,withtheenhancementofsteelblank，smechanicalstrength,itsformabilityisworseneddramatically.ItisdifficulttoapplythetraditionalcoldstampingtechnologyintothefieldofpressingHSS.Thus,thehotstampingtechnologyofmartensiticsteelblankisappliedasanewtechnology,whichcombinesmetalthermoplasticformingmethodandwater-coolingmouldquenchingprinciple.Inthispaper,bo