EQ70钢激光电弧复合焊焊接热循环及其对热影响区组织演变的影响  

Welding thermal cycle of the laser-arc hybrid welding of the EQ70 steel and its effects on the microstructure evolution of the heat affected zone

作　　者：鲍亮亮 王勇[1] 张洪杰[1] 徐良 韩涛[1] BAO Liangliang;WANG Yong;ZHANG Hongjie;XU Liang;HAN Tao(China University of Petroleum(East China),Qingdao 266580,China;China Construction Industrial&Energy Engineering Group Co.,Ltd.,Nanjing 210000,China;Harbin Modern Welding Technology Co.,Ltd.,Harbin 150028,China)

机构地区：[1]中国石油大学(华东),青岛266580 [2]中建安装集团有限公司,南京210000 [3]哈尔滨现代焊接技术有限公司,哈尔滨150028

出　　处：《焊接学报》2021年第3期26-33,I0003,I0004,共10页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51874345);山东省自然科学基金资助项目(ZR2018MEE012,ZR2019MEE111);山东省重点研发计划项目(2017CXGC0812).

摘　　要：采用Visul Environment软件建立了EQ70钢激光电弧复合焊的三维模型,并利用SYSWELD软件对激光电弧复合焊焊接温度场进行了有限元数值模拟,结合热电偶测温法和热影响区的微观组织表征分析了激光电弧复合焊热循环特点及其对热影响区组织演变的影响.结果表明,采用双椭球体+峰值递增锥体组合型热源可以准确模拟复合焊温度场,电弧区、过渡区、激光区相同热影响区微区具有相近的热循环,热影响区加热速度可达400℃/s,1100℃以上停留时间为0.79~1.33 s,t8/5为4~6 s.粗晶区、细晶区组织为板条马氏体,临界区组织为马氏体+晶界碳化物,亚临界区组织为回火马氏体.激光电弧复合焊具有快速加热、高温停留时间短的特点,在一定程度限制了奥氏体晶粒的长大,粗晶区和细晶区平均晶粒尺寸分别为42.7,19.8μm.The Visul Environment software was used to establish the 3D model of the laser-arc hybrid welding joint of EQ70 steel.The temperature field of the laser-arc hybrid welding was numerically simulated by the SYSWELD software.The thermal cycle characteristics of the laser-arc hybrid welding and its effects on the microstructure evolution of the heat affected zone(HAZ)were analyzed,combined with the thermocouple thermometry and microstructure characterization.The results shown that the combined heat source with double ellipsoid and peak increasing cone could accurately simulate the temperature field of the laser-arc hybrid welding,and the arc zone,transition zone and laser zone had similar thermal cycles in the same HAZ micro-zones.The HAZ heating rate can reach to 400℃/s,the dwelling time above 1100℃was 0.79−1.33 s,and the t8/5 was 4−6 s.The coarse grained HAZ(CGHAZ)and the fine grained HAZ(FGHAZ)were mainly comprised of lath martensite.The microstructure of the inter-critically HAZ(ICHAZ)was martensite and grain boundary carbides.The sub-critically HAZ(SCHAZ)composed of tempered martensite.The rapid heating and short high temperature dwelling time of the laser-arc hybrid welding limited the austenite grain growth to some extent,and the average grain size of the CGHAZ and FGHAZ were 42.7μm and 19.8μm,respectively.

关 键 词：EQ70 激光电弧复合焊 热循环 热影响区 

分 类 号：TG404[金属学及工艺—焊接]