铝镁合金双丝脉冲MIG焊接头组织与力学性能分析  

Analysis on Microstructure and Mechanical Properties of Aluminum-magnesium Alloy Double-wire Pulsed MIG Welding

作　　者：孙宏坤 陈毅腾 李超[2] SUN Hongkun;CHEN Yiteng;LI Chao(Guangzhou Bureau of Naval Equipment Department,Guangzhou 510250;Hebei University of Science and Technology,Shijiazhuang 050091)

机构地区：[1]海装驻广州地区第三军事代表室,广州510250 [2]河北科技大学,石家庄050091

出　　处：《广东造船》2022年第4期66-69,共4页Guangdong shipbuilding

摘　　要：为了提高焊接效率和质量,采用双丝脉冲MIG焊完成4mm厚铝镁合金平板焊接。分析了接头组织及力学性能,并与单丝MIG焊接头进行对比。结果显示:双丝脉冲MIG焊可显著提高焊接速度,焊缝无明显气孔缺陷,焊缝中心为致密的等轴晶组织;相对于单丝焊接头,双丝焊熔合线附近柱状晶区变窄;两种焊接接头具有相同的显微硬度变化规律,最小值出现在焊缝中心,热影响区软化程度双焊丝焊小于单丝MIG焊;接头拉伸试样均在焊缝中心发生断裂,屈服强度和抗拉强度均符合标准,且与单丝焊差别不大。In order to improve the welding efficiency and quality,the 4mm thick aluminum-magnesium alloy plate is welded by double-wire pulse MIG welding.The microstructure and mechanical properties of the joint are analyzed,and compared with the single-wire MIG welded joint.The results show that double-wire pulsed MIG welding significantly increases the welding speed,the weld has no obvious porosity defect,and the center of the weld is a dense equiaxed grain structure.Compared with the single-wire welded joint,the columnar grain area near the fusion line in the double-wire welded joint is narrower.The two welded joints have the same variation law of microhardness,and the minimum value appears at the center of the weld and the softening degree of the heat-affected zone is lower than that of the single-wire MIG welding;the tensile specimens of the joints all break at the center of the weld,and the yield strength and tensile strength are not much different from that of single wire welded joint.

关 键 词：脉冲MIG焊 双丝MIG焊 铝镁合金 力学性能 金相组织 

分 类 号：TG444[金属学及工艺—焊接]