254SMO超级奥氏体不锈钢宽弧/双丝MIG焊接接头组织与耐蚀性能研究

Microstructure and Corrosion Resistance of 254SMO Super Austenitic Stainless Steel Wide Arc/Double-Wire MIG Welded Joints

分别采用宽弧脉冲MIG焊接技术、双丝脉冲MIG焊接技术和普通脉冲MIG焊接技术对254SMO超级奥氏体不锈钢进行焊接,对比焊接效率,检测不同焊接工艺下焊接接头的耐点蚀性能,并使用扫描电镜(SEM)、能谱仪(EDS)对焊缝组织进行分析。结果表明,254SMO焊接接头的点蚀主要源于焊缝未混合区的Mo偏析。宽弧脉冲MIG焊接和双丝脉冲MIG焊接相对于普通脉冲MIG焊接,其接头的耐点蚀性能无明显区别,焊接效率分别提升至普通脉冲MIG焊接的1.2倍和2.5倍。

254SMO super austenitic stainless steel was welded by using wide arc pulse MIG welding technology,double-wire pulse MIG welding technology and normal pulse MIG welding technology, respectively, and the welding efficiency was compared. The pitting resistance of welded joints under different welding processes was detected, and the weld microstructure was analyzed by using SEM and EDS. The results show that the pitting corrosion of 254SMO joints is mainly caused by Mo segregation of unmixed zone in weld. Compared with normal pulse MIG welding, wide arc pulse MIG welding and double-wire pulse MIG welding joints have no obvious difference in joint pitting resistance performance, and the welding efficiency is 1.2 times and 2.5 times of that of normal pulse MIG welding, respectively.