MAG和激光扫描-电弧复合焊X80钢接头组织和性能  

Microstructure and properties of MAG and oscillating laser arc hybrid welded X80 steel

作　　者：李泽宇 徐连勇[1,2] 郝康达 赵雷 荆洪阳[1,2] LI Zeyu;XU Lianyong;HAO Kangda;ZHAO Lei;JING Hongyang(Tianjin University,Tianjin,300350,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin,300350,China)

机构地区：[1]天津大学,天津300350 [2]天津市现代连接技术重点实验室,天津300350

出　　处：《焊接学报》2022年第5期36-42,I0005,I0006,共9页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52025052)。

摘　　要：在激光焊接打底情况下,对比研究了熔化极活性气体保护电弧焊(MAG)和激光扫描-电弧复合焊(OLAHW)工艺对X80管线钢接头成形、显微组织和力学性能(显微硬度、拉伸性能和冲击韧性)的影响规律.结果表明,两种工艺下均能获得无气孔、夹渣和裂纹缺陷,成形良好的焊接接头,接头组织均主要由针状铁素体(AF)和M-A组元组成.因为更小的焊接热输入和更快的冷却速度,以及激光束扫描促进形核作用,OLAHW填充接头组织中形成较MAG填充接头更多的针状铁素体和更细小的M-A组元. MAG和OLAHW两种填充工艺下接头平均显微硬度和拉伸强度接近,但OLAHW焊接接头的硬度变化相对MAG接头更平缓、硬度值波动较小,且OLAHW填充接头热影响区和焊缝区冲击吸收能量分别为277和217 J,较MAG填充接头分别提高了64%和42%.Metal active gas welding(MAG) and oscillating laser arc hybrid welding(OLAHW) of X80 pipeline steel were carried out with backing weld by laser, the joint formation, microstructure and mechanical properties(microhardness, tensile properties and impact toughness) were studied. The results showed that sound joints without defects of pores, slag inclusion and crack were obtained by both the two processes. The joint microstructure was mainly composed of acicular ferrite(AF) and M-A components. Because of lower heat input, faster cooling rate and more nucleation sites promoted by the oscillated laser, more acicular ferrite and finer M-A components were formed within the OLAHW filled joints than those within MAG filled joints. The average microhardness and tensile strength of the joints obtained by the two filling processes were almost the same, but the hardness variation of OLAHW joints is gentler with less fluctuation. The impact energy of heat affected zone and weld zone of OLAHW filled joints were 277 and 217 J respectively, which is 64% and 42% higher than those of MAG filled joints.

关 键 词：X80管线钢 MAG焊 激光扫描-电弧复合焊接 微观组织 冲击韧性 

分 类 号：TG444[金属学及工艺—焊接]