6W_5Mo_4Cr_2V高速钢深冷处理微观组织结构的分析

36720027上海交通大学学报JOURNALOFSHANGHAIJIAOTONGUNIVERSITYVol.36No.7Jul.2002:2001-08-27:(50075053):(1969-),,,,.:1006-2467(2002)07-0905-036W-5Mo-4Cr-2V李　雄1,　李士燕2,　张鸿冰3,　阮雪榆1(1.,200030;2.,730050;3.,200233):借助SEM、TEM和X-射线衍射仪研究了深冷处理对6W-5Mo-4Cr-2V高速钢微观组织结构的影响.研究表明,深冷处理不仅可使残余奥氏体减少,而且可细化马氏体孪晶,促使析出纳米级碳化物,并附着在马氏体孪晶带上.深冷处理既能提高材料的硬度,也使材料的韧性略有增加.对磨损表面进行SEM观察发现,深冷试样的磨损形貌迥异于未深冷试样,说明它们的磨损机制不同.深冷处理使6W-5Mo-4Cr-2V高速钢耐磨性提高的主要原因是马氏体孪晶的细化和碳化物的析出.:高速钢;深冷处理;微观组织;磨损;残余奥氏体;碳化物;马氏体:TG113.1:AMicrostructureof6W-5Mo-4Cr-2VHighSpeedSteelafterCryogenicTreatmentLIXiong1,LIShi-yan2,ZHANGHong-bing3,RUANXue-yu1(1.Dept.ofPlasticityFormingEng.,ShanghaiJiaotongUniv.,Shanghai200030,China;2.Inst.ofToolsandDies,GansuUniv.ofTechnology,Lanzhou730050;3.Dept.ofMaterialsEng.,ShanghaiInstituteofTechnology,Shanghai200233)Abstract:Effectofcryogenictreatmentonthemicrostructureof6W-5Mo-4Cr-2Vhighspeedsteelwasin-vestigatedbymeansofSEM,TEMandX-raydiffractometer.Theresultsshowthatcryogenictreatmentcannotonlyreduceretainedaustenite,butalsofinemartensitetwinsandlettoprecipitatecarbidewithnanometersizeatmartensitetwins.Bothhardnessandtoughnessofthesteelareincreasedaftercryogenictreatment.ItisdiscoveredfromobservingwearingsurfacewithSEMthatthetopographyofspecimenaftercryogenictreatingisdifferentfromthatofuntreatingspecimen,implyingthatcryogenictreatmentcanchangewearmechanism.Theimprovementofthewear-resistanceof6W-5Mo-4Cr-2Vhighspeedsteelisduetothefinemartensitetwinsandcarbideprecipitation.Keywords:highspeedsteel;cryogenictreatment;microstructure;wear;retainedaustenite;carbide;martensite,-130C[1,2].,.29[3];Konik,,HRC0.51.7,35[4];[4][5].,,[3,6],,.6W-5Mo-4Cr-2V,SEM,.16W-5Mo-4Cr-2V,1235C560C3,-196C12h,():w(C)=0.87%,w(W)=5.56%,w(Mo)=4.60%,w(Cr)=3.86%,w(V)=1.78%,w(Si)=0.18%,w(Mn)=0.37%,w(P)=0.0283%,w(S)=0.028%.(TEM)0.2mm,0.05mm(),,H-600.HR-150DJB6,10mm10mm55mm,,S-520.-.45#,870C.:20N,800r/min,1h.0.1mg.X-(SEM),SEM.X-D/MAX-2400.22.116W-5Mo-4Cr-2VTEM.1(a)(b),(c)(d);(a)(c),(b)(d).,,,2070nm,1020nm,..TEM,;,610nm.TEM,M6C.1TEM(105)Fig.1TEMmicrographofhighspeedsteel,,,;(1).,,,,..2.2HRC1.5,(23J/cm2,23.5J/cm2).2(a)2(b)SEM,,,.,,.906上　海　交　通　大　学　学　报362SEMFig.2SEMmicrographoftheimpactedsection2.31X-.1,,.,,.1Tab.1Theparametersofmarsteniteandretainedaustenitecalculatedundervariousconditionsw(C)1.0430.791.0350.771.0320.75/nmw(C)0.36141.510.36121.450.35951.073SEM.,.,;,,.,,.(4),,;,,.,.[8],,.,[9];,,;,.3SEMFig.3SEMmicrographofthewornsurface4SEMFig.4SEMmicrographofthecross-section,1.5..3(1),.(2),.(3),,..(4),,.:[1],,.N•¶œÍ[J].,1987,27(2):86-90.[2]CollinsDN.Deepcryogenictreatmentoftoolsteels:areview[J].HeatTreatmentofMetals,1996,23(2):40-42.(910)9077李　雄,等:6W-5Mo-4Cr-2V高速钢深冷处理微观组织结构的分析.,Lp,p2p3.,,,p,.3,,.,,,..,.:[1],,.[M].,,.:,1982.[2].[M].:,1989.[3]HEDan-nong,TAOHong-zhi,BAOXiang-jun,etal.Researchontherelationshipbetweenthefric-tioncoefficientsoflubricantsfordrawingandblankholderforce[J].Tribology,2000,20(3):223-225.[4].[M].:,1979.[5]HaoS,KlamechiBE,Ramalingam.Frictionmea-surementapparatusforsheetmetal[J].Wear,1999,224(1):1-7.[6]MatuszakA.Factorsinfluencingfrictioninsteelsheetforming[J].JournalofMaterialProcessingTechnology,2000,106(1):250-253.[7],,,.[J].,2002,36(4):456-458.YANGJian-hua,PANWei,HEDan-nong,etal.Experimentaltestingofdraw-beadrestrainingforceinsheetmetalforming[J].JournalofShanghaiJiao-tongUniversity,2002,36(4):456-458.(907)[3].[J].,1992,(1):47-51.HUANGShi-min.Theapplicationofcoldtreatmentinindustry[J].JournalofMaterialsEngineering,1992,(1):47-51.[4],,.K9•¶œÍN[J].—˜—,1990,28(9):83-88.[5].[D].:,2000.[6],,.[J].,2000,20(4):276-279.LIShi-yan,CHENChang-feng,LIXiong.Effectofcryogenictreatmentontheabrasive-resistanceofT12steel[J].Tribology,2000,20(4):276-279.[7].[M].:,1993.[8].[M].:,1992.[9],.LD1[J].,1997,21(1):26,39.LIGang,LIShi-yan.Studyofthemachanicalprop-ertiesofLD1steelaftercryogenictreatmentandtheformdistributionsandsubstructureofretainedaustenite[J].MaterialsforMechanicalEngineer-ing,1997,21(1):26,39.910上　海　交　通　大　学　学　报36