中碳含钒微合金非调质钢析出与热变形行为的研究

《中碳含钒微合金非调质钢析出与热变形行为的研究》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、万方数据江苏大学硕士学位论文ABSTRACTInthelastfewyears，thevanadiummicroalloyednon-quenchedandtemperedsteelhasbeenwidelyusedinsuchasautomotive，petroleumandmachinerymanufacturingindustryforitslowcostandhighperformance．Generally,duetolackoftheheattreatment，thiskindofsteelhasahig

2、hproductionefficiencybutalowtoughness，andthegrainofVNcouldsignificantlyfacilitatethenucleationofintragranularferrite(IGF)，whichmakethegrainrefining．Therefore，inordertoobtainagoodoverallperformance，theprocessparametersatthethermalprocessshouldbeadjustedwhichcoul

3、dpromotethenucleationrateofIGF．Inthispaper，forthepurposeofstudyingtheprecipitationandthermaldeformationbehaviorofthevanadiummicroalloyednon—quenchedandtemperedsteel，twoexperimentalprocesseswerearranged，whichwerethestressrelaxationandsingle—passthermalcompressio

4、n．Theprecipitationkineticscurvesandtheconstitutiveequationwereobtainedbasedontheexperimentresults．Throughthestressrelaxation，thevanadium-carbonitrideprecipitatedbehaviorinaustenitewereresearchedunderdifferentexperimentalconditions，theresultindicatedasfollows：Th

5、edownwardtrendofstressslowdowneventhestressplateauappearsasthevanadium-carbonitrideprecipitate；Withtheendofthevanadium—carbonitrideprecipitating，thedownwardtrendofstressretumtothepreviousstatus，insomeconditions，therecouldbesecondaryeventhirdprecipitation，butthe

6、effectofstoppingthestressfromdecreasingisreduces；TheshapeofPTTcurvesgotfromthestressrelaxationcurveshasadoubleCtypecharacteristic．Andthefastestprecipitationtemperatureis650。Cbelow800℃，v(c，N)beginstoprecipitateat4sandendsat10．5s，thevanadium-carbonitrideprecipita

7、teatthistemperaturehasahighcarboncontent；inthemeantime，thefastestprecipitationtemperatureis870℃beyond800。C，V(C,N)beginstoprecipitateat1．6sandendsat3．5s，thevanadium-carbonitrideprecipitateatthistemperaturehasahighnitrogencontent。Alargeamontofvanadium．carbonitrid

8、eparticlesaredispersivedistributionat870℃and900。Cafterquenching．Theresultsoftwotypesofsteelwhicharevanadium-microalloyedsteelandcarbon—-manganesesteelbythesingle--passtherma