欢迎来到天天文库
浏览记录
ID:33101485
大小:7.85 MB
页数:60页
时间:2019-02-20
《weldability+of+ultra-high+strength+pipeline+steel+x120》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、IIWuhanUniversityofScienceandTechnologyAbstractX120ultrahighstrengthpipelinesteelwithhighstrengthandgoodlowtemperaturetoughnesswasobtainedbymeansofultralowcarbondesign,microalloyingandTMCPprocessing.Themicrostructureofthisstee“SdominantlyupperbainiticferriteTheadditionofmicroaIloyin
2、gelements(Nb,VTi,Zr)pinnedtheprioraustenitegrainboundaryandledtosmallaustenitegrains.TMCPprocessingresultedinpan-·cakeshapeaustenitegrainsandfinallyfine-·grainedmicrostructureinthebasemetalsteelplate.Themicrostructuralevolutionincoarse—grainedregionofheat.affectedzone(CGHAZ)ofX120ul
3、trahighstrengthpipelinesteelwasinvestigatedbymeansofthermalsimulationonaGleeble3500.TheCOntinuouscoolingtransformationcHrvesofsimulatedHAZrSH—CCT)wereobtainedsimultaneously.Asthecoolingraterangedfrom0.1。C/sto60。C/s.thepredominantlybainiticmicrostructurewasobtainedinthesimulatedCGHAZ
4、.BainitewasobtainedinthesimulatedCGHAZwhentheheatinDutofweldingwas12~25kJ/cm.TheVickershardnessofCGHAZwasbetween291-303HV10.Theimpacttoughnessatroomtemperaturewashighandstable(208~225J、.ThesimulatedresultsrevealedthatX120steelCanbeweldedinawiderangeofweldingheatinput.Afastcoolingpro
5、cesswasintroducedtoimprovethetoughnessoftheCGHAZ.TheweldingthermalcyclewasvariedinwhichboththeholdingtimeathightemperatureaboveAc3(瑚andcoolingtimefrom800to500。C(ts/5)wereshorten.Shorten臼ledtothinHAZwidthandfineprioraustenitegraininfusionline(FL)andCGHAZ:whiletheshortents/5resultedin
6、thethinnerbainite1ath.Themartenist.austinitefM.A)constituentsinfusionlinewerereducedandtheirmorphologywaschangedintothinfilm-like.AllthesefactorsplayedabeneficialroleinimprovingtoughnessofHAZofpipelinesteelX120.AccordingtotheSH.CCLtheheatinDutof21kJ/cmwaschosentoweldtheX120baseplate
7、utilizingthree-wiresubmergedarcweldingandtheabove.mentionedfastcoolingtechnique.Themicrostructureintheheat.affectedzonewasinvestigatedbymeansofopticalmicroscopyandscanningelectronmicroscopy.Thehardnessofheat.affectedzonewasmeasuredbyVickershardnessindenter.ResultsshowthattheX120line
8、pipeweldingjointhad
此文档下载收益归作者所有
点击更多查看相关文章~~