3、残余奥氏体含量的变化对冲击性能具有一定的影响。关键词:2.25Cr1Mo钢焊缝热处理工艺残余奥氏体冲击韧性中图分类号:TG456Effect of residualaustenite content on impact toughness of the fillermetalof2.25Cr1Mo steel1,2 1111QU Yuebo HUANG Xinquan CAO Bin CAIZhipeng PAN Jiluan (1. Dept. of Mechanical Engineering, Tsinghua University, B
4、eijing, 100084;2. School of Mechanical Engineering ,Xiangtan University, Xiangtan,411105 )Abstract:Impacttoughnesstestswere used tocompare twodifferentkinds oftemperheattreatmentforthe fillermetalof2.25Cr1Mosteel.In thefirsttemperprocess, thetoptemperature is720℃andtheholdin
5、gtimeisfor2hours.Theothertempertreatmentincludes680℃and12hours.Thefirstheatingprocess shows a betterimpacttoughness.Tostudywhatcauses the difference,the jointsprocessed with the firsttempertreatmentwere dipped intoliquidnitrogen todecomposeresidualaustenite in welds.Thelater
6、testsshowthatimpacttoughness isdeceasedcausedbythesuppercooling,whichsuggestsaustenite maybe an importantfactorforweldstoughness. Tovalidatetheassumption,magnetopolarizationintensityandelectronbackscattered diffraction ofdifferentsampleswereinvestigatedtoquantifyresidualaust
7、enitequalityanddistributionthrough vibration sample magnetometer(VSM)and Electron BackScatteringDiffraction (EBSD)separately.Afterthefirsttemperprocess,the weldingmetalhasabout3%residualaustenite qualityinvestigated byVSM,and has0.2%afterthe second temperprocess;On the other
8、hand ,ithas about3.49%residualaustenite qualityinvestigatedbyEBSDafterthe f