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ID:32992264
大小:3.05 MB
页数:56页
时间:2019-02-18
《astm4130钢焊接接头组织与性能分析》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、、’IntheMax.hardnesstestofweldingHAZ,Max.hardnessvalueofHAZpresentstothevicinityofweldinterface,whichachievesatroomtemperature,duedtotheformationofbrittlemartensite,reaching566I--IVl0.Thepeakvaluesreduceto455"--490HVloafterpreheatingat150"C,200"Cand250"C,whichdroptO345HVIoat300"C.Testingprovedthatpr
2、eheatingcalleffectivelydecreasethecontentofhardeningstructure,relievingthesensitivityofASTM4130steel.Thecoarse—grainHAZs,whichareintheimplanttestandMax.hardnesstestofweldingHAZ,consistspredominantlyofmartensiteandbainite.Themicrostructuresofweldmetalasweldedareacicularferriteandasmallamountofpearli
3、te,andwhichofHAZaremartensite,ferriteandbainite.AfterPWHT,themicrostructureofweldmetalconsistspredominantlyofferrite,asmallamountofpearliteandgranularcarbide,whichofHAZarecomprisedoftemperedsorbite,ferriteandbainite.Thecarbidegraduallyprecipitatesandthestructurebecomesfineasprolongingthesoakingtime
4、.Withprolongingthesoakingtime,thetensilestrengthvaluesincreasefirstandthendecrease,andthehardnesslevelsofweldmetalhavealittlechange,whilewhichofHAZandbasematerialgraduallyreduce.Maximumhardnessvaluepresentstothevicinityofweldinterface.Thehardnessvaluesreducegraduallyasincreasingthedistancefromweldi
5、nterface,reachingminimumvaluenearby3"一4mmfromweldinterface,andthereisanobvioussofteningphenomenoninHAZ.Theimpacttestresultsshowthatweldandfusionzonearetheweakestpartsofweldedjoints,andthevaluesoffusionlinetendtofluctuatewildly.Basematerialshavethehighesttoughness.ThereisthusagoodimprovementintheHAZ
6、toughnessinspiteofminorchangesinweldandfusionlineasprolongingthesoakingtime,relatedtothereductionofcoarsenedphasesandupperbainiteinthemicrostructure.Keywords:ASTM4130steel,Preheat,Post—weldheattreatment,Weldedjoints,MicrostructuresandpropertiesIII、\目录第一章绪论⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯.11.1课题意义⋯⋯⋯
7、⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11.2中碳调质钢焊接性分析⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11.3国内外研究现状⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯31.3.1中碳调质钢焊接研究现状⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯31.3.24130钢焊接研究现状⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯61.3.3焊接接头强韧化研究现状⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯
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