X80管線鋼焊接熱影響區(qū)組織與性能研究.pdf

1、西安石油大學碩士學位論文X80管線鋼焊接熱影響區(qū)組織與性能研究姓名：徐學利申請學位級別：碩士專業(yè)：機械工程指導教師：辛希賢20060510英文摘要subject：AstudyonthemicrostructureandpropertiesintheltAZofX80pipelinesteelMajor：MechanicalEngineeringName：Xuxueli(signature)絲碰￡!；Instructor：Xinxixia

2、u(signature))(洫Zjg詛d，ABSlRAC』ThemechanicsproperfiesandmicrostructureofbasemctalandweldedjoimforX80pipelinesteelwereinvestigatedbyoscilloiMPacttoughnesstestmicro—hardnesstest，opticsmicroscopeandTEMtestTheresultsshowedthat

3、firetoughnessofbasemetalandweldedjointsofX80wasgoodandtheweldWaSbesl11hetoughnessofcoarsegrainedregionintheHAZwasreducedbecauseofweldingthermalcycleandfonningbrirtlenessmicrostructureThemicrostructureareaeicularfetritewi

4、thalinleofferritesideplateinbasemetaltypicalacicularfetxiteinweldmetalmadgrainbainiteincoarsegrainedregionoftheHAZThehardnessWaShighestinHAZadjacenttotheweldbondandthengmduallydescendedtothelevelofbasemetalbeyondtheweldb

5、ondTheinfluenceofweldthelrnalcycleontoughnessandmicrostructureincoarsegrainedregionintheheataffectedzone(HAz)ofx一80pipelinesteelwasinvestigatedbyweldthermalsimulationtechnique，metallographytransnlissionelectronmicroscopy

6、(TEM)，theinstrumentedcharpyiMPacttouglmesstestandfracturetouglmesstestThetestresultsshowedthattherearedifferentmicrostructureinsimulationcoarsegrainedregionofX80pipelinesteelundersixdifferentweldthermalcycleconditionsWhe

7、nthethermalcyclingparametersaresman，themierostructureofcoarsegrainedregionisprimarilylowerbainiteandlathmartensite，andwhenhethennalcyclingparametersincrease，granularisthemainThestructuralmorphologyofM—Aislandswaschangedf

8、romthinmadshortbarstolmgelongbarsorlargepieee—like，anddistributedfromgrainboundarytogramAttheSOrlletime，thellnllthoroftheMAislandsincreasemadtoughnesswouldgetworseTherelationshipbetweenmierostnlctmeandtoughnessofCOOlSOgr

9、ainedregioninxgOpipelinesteelduringdoubleweldingfl_1e]malcyclewasinvestigatedusingweldingthmmalsimulationteclmique，opticsandTEMexperimentasweeasiMPacttouglmessmadCTODtestThetoughnessof“reheatedcoarsegrainedregionwhichwas

10、ellaractelisticofCIitiealcoalsegrainedregionwaslowestasthesecondpeaktelnperalurewasintWOphase(刊v)temperaturerangeThelocalbriulementincriticalcoarsegrainedregionwascausedmostlybyislandStl11CtnreKeywords：X80pipelinesteel，c