X120管线钢激光-电弧复合焊接头组织及硬度分析  

Microstructure and Hardness Analysis of Laser-arc Hybrid Welding Joint of X120 Pipeline Steel

作　　者：刘博 王媛媛 李彬 LIU Bo;WANG Yuanyuan;LI Bin(CRRC Datong Electric Locomotive Co.,Ltd.,Datong 037000,Shanxi,China)

机构地区：[1]中车大同电力机车有限公司,山西大同037000

出　　处：《焊管》2021年第10期19-23,共5页Welded Pipe and Tube

摘　　要：针对X120管线钢焊接过程中热影响区粗晶区韧性降低的问题,采用激光-电弧复合多层多道焊接工艺进行焊接试验,并对不同焊接线能量下焊接接头热影响区粗晶区的组织变化情况和显微硬度进行了分析。结果显示,焊接接头热影响区粗晶区的组织主要为马氏体+针状铁素体+粒状贝氏体,随着焊接线能量的提高,晶粒尺寸增大;在熔合线附近晶粒的大小呈现梯度变化,组织也由马氏体向粒状贝氏体转化;焊接接头硬度随着焊接线能量的增大而减小。In view of the decrease of toughness of coarse grain zone in heat affected zone during welding of X120 pipeline steel,the welding test of X120 pipeline steel was carried out by using laser-arc hybrid multi-layer and multi-pass welding process,and the microstructure changes and microhardness of coarse grain zone in heat affected zone of welded joint under different welding line energy were analyzed.The results show that the microstructure of coarse grain zone in HAZ of welded joint is mainly martensite,acicular ferrite and granular bainite.With the increase of welding line energy,the grain size increases.Near the fusion line,the grain size shows a gradient change,and the microstructure also transforms from martensite to granular bainite.The hardness of welded joint decreases with the increase of welding line energy.

关 键 词：X120管线钢 激光-电弧复合焊 微观组织 显微硬度 

分 类 号：TG407[金属学及工艺—焊接]