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ID:37393934
大小:8.09 MB
页数:70页
时间:2019-05-23
《提高轴承钢性能的热处理工艺研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、西南交通大学硕士学位论文提高轴承钢性能的热处理工艺研究姓名:王林梅申请学位级别:硕士专业:材料科学与工程指导教师:杨川20081101西南交通大学硕士研究生学位论文第1I页到的组织组成为针状马氏体+下贝氏体+残余奥氏体+残余碳化物。等温初期,贝氏体转变较快,下贝氏体随等温时间延长而长大,等温到一定时间后下贝氏体转变速率下降,贝氏体不再继续长大。贝氏体转变量在45.1%左右时,轴承试样的综合性能最佳。耐磨性能比马氏体淬回火试样提高了47.5%。GCrl5经马氏体淬回火处理,试样断裂机制为微孔聚集型断裂,而经贝氏体等温淬火处理后,断裂机制转变为解理断裂。贝氏体转变后试样表面的残余压应力高于
2、马氏体淬回火组织。关键词:轴承钢,细化碳化物,残余奥氏体,下贝氏体,MfB复合组织,性能西南交通大学硕士研究生学位论文第lII页AbstractRecently,withthefastdevelopmentofwindelectricpowerprojectsand11j曲speedrailway,RollingBearingiswidelyusedinengineering,andtheservicelifeisrequiredtobecomehigherandhigher.Thispaperbasedonimprovingthepropertiesofbearingsteelsth
3、roughheattreatment,determinedthemicrostructureandmechanicalpropertiesofseveraldomesticandextemalbearingsteelsamples.andtheretentionofausteniteofdifferentsamplesweremeasuredbymeansofXRD.SEMwasusedtOanalysisthedifferenceinstructureofseveralbearingsteelsamples.Onthisbasis.thecarbideWasrefinedbyvari
4、ouspretreatmentprocess,andthemicrostructureandmechanicalpropertiesofsamplesweremeasuredafterdifferentheattreatment.Theresidualaustenitecontentwascontrolled,indifferentrangesbyultimatetreatmenttechnology,themicrostructuresandthemechanicalpropertiesareexamined.andtheinfluenceofresidualaustenitecon
5、tentonpropertiesofbearingsteelshavebeenanalyzed.Themicrostructuresandmechanicalpropertiesofbearingsteelwereinvestigatedafteraustemperingfordifferentisothermalholdingtime.Bainitetransformationrateanditseffectonbearingsteelpropertieswereresearched.SEMwasusedtoanalysisfracturemechanismandXRDwasused
6、tomeasuretheresidualstressofsamplesaftermartensiticquenchingandbainitehardening.Basedontheresearchwork,someconclusionsaredrawnasfollows:Themartensitecontentofshaftsleeveandaxostyleofexternalbearingstee】arecontroledrespectivelyindifferentranges.Comparingwithdomesticbearing,theexternalbearingsteel
7、shavewelldistributedfinelycarbides,andIowerresidualaustenitecontent.Indeed.theresidualaustenitewaseliminatedcompletelyinsomeexternalbearingsteels.Experimentalresultsindicatethattheexternalbearingsteelexhibitsabeaerwearresist
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