325-paper-垂直短裂紋論文－英文

1、1本文通過模擬試驗(yàn)揭示了軋輥接觸疲勞過程垂直短裂紋的形成機(jī)制，具有明顯的學(xué)術(shù)創(chuàng)新性，對于指導(dǎo)支承輥使用有一定價(jià)值，文章結(jié)構(gòu)嚴(yán)謹(jǐn)、文理通順，未泄露企業(yè)技術(shù)秘密。全文篇幅太長，一些文獻(xiàn)引述、第3節(jié)結(jié)果與討論、參考文獻(xiàn)可適當(dāng)刪減。VerticalShtCrackBehaviItsApplicationinRollingContactFatigueChanganWangHSMPBaoshanIronSteelCompanyShanghai200

2、941ChinaABSTRACTTheverticalshtcrackbehavipresentedinrollingcontactfatigueofmediumcarbonbainiticsteelbackuprollundertheconditionsoflowcontactpressurewaterlubricationpurerollingwerestudied.Theinitiationpropagationbehaviofv

3、erticalshtcrackweretracedbymicroscopicobservationduetoitsobservabilityonthesurfaceofthespecimen.Itisfoundthataftertheshtcrackinitiatesquicklypropagatestoacertaindepthfromthecontactsurfacetheverticalshtcrackwillstoppropag

4、atingfalargenumberofcycles(from104to3~5?105cycles)howeverwhilethenumberofcyclesisuptotheinitiationlifeofrollingcontactfatigue(about3~5?105cycles)theverticalshtcrackrepropagatesatahighpropagationratealongthecircumferentia

5、ldirectionofthespecimenparalleltothecontactsurface.Basedontheobservedunpropagatingrepropagatingbehavisofverticalshtcracktheinitiationlifesurfacedistresslifeofrollingcontactfatigueofthebackuprollerwasmeasuredthenthemechan

6、ismofrollingcontactfatiguewasdiscussed.KEYWDS:rollingcontactfatigueverticalshtcrackinitiationlifebainiticsteel1.IntroductionRollingcontactfatigue(RCF)isamainfailuremodeofrollerwheelrailitresultsinpittingspallingoncontact

7、surface.Duringthehotrollingthepittingspallingfmedonthesurfaceofrollercandegradethequalityofmanufacturedsteelsheetgreatlytheymustbepreventedinpractice.Inhotrollingfactythefatiguefailureonthesurfaceofrollerispreventedbygri

8、ndingthesurfaceawayaftercertainwkingtimewithcertainthicknesshoweveratpresenttheabrasivethicknessadoptedineachgrindingistoolargethenresultsinasignificantlydecreasingintheutilizedlifeoftheroller.Itimpliesthattheabrasivethi

9、cknesscanbefurtheroptimizedonthebasisoftheaccurateundersttotherollingcontactfatigue(RCF)behaviof3conditionsoflowcontactpressurewaterlubricationpurerolling.Theinitiationpropagationoftheverticalshtcrackweretracedbymicrosco

10、picobservation.Basedontheobservedbehavisoftheverticalshtcracktheinitiationlifesurfacedistresslifeofrollingcontactfatigueoftherollerwasmeasuredthenthefailuremechanismofrollingcontactfatiguewasdiscussed.2.ExperimentalProce

11、dureTherollingcontacttestofmediumcarbonbainiticsteelrollerwasperfmedonaJPM－1BtypetwodiscRCFwearmachine.Theupperrollerwasmadeofmediumcarbonbainiticsteel(40Cr3MoVsteel)whichmodeledthebackuprollerofhotrollingmachinewasmainl

12、yinvestigatedintheexperimentthelowerroller(drivingroller)wasmadeofCr12MoVsteel.ThegeometriesofthetworollersareillustratedinFig.1thechemicalcompositionsofthematerialsarelistedinTable1.Themicrostructuresmechanicalpropertie

13、sarelistedinTable2Table3respectively.Fig.1Shapessizesofthespecimensinrollingcontactfatiguetests(a)upperroller(b)lowerrollerTable1Chemicalcompositionofthematerialsfrollers(Wt%)TestrollersCSiMnSPNiCrMoVUpperroller0.430.420

14、.520.0260.0230.153.430.600.12Lowerroller1.500.400.350.0240.020120.500.20Table2MicrostructuresofthematerialsfrollersUpperroller(40Cr3MoV)Lowerbainitemainlytemperedmartensitepartiallyundissolvedcarbidescarcely.Lowerroller(