焊丝匹配对304/Q345异种钢激光-MAG复合焊接头组织和力学性能的影响

Effects of filled metal on microstructure and mechanical properties of 304/Q345 dissimilar steel laser-MAG hybrid welded joints

采用激光-MAG复合焊方法,选择Cr,Ni含量不同的ER308L,ER309L不锈钢焊丝作为填充材料,填充形式分别为ER308L+ER309L(其中ER309L作为过渡层)和单独ER308L,对304奥氏体不锈钢和Q345低合金钢进行焊接,对所获得的焊接接头进行显微组织、基本力学性能进行分析研究。结果表明:不同的焊丝填充形式下,异种接头焊缝处均出现了下贝氏体、δ-铁素体和奥氏体。焊缝硬度值最高,ER308L填充焊缝达到HV489,ER309L+ER308L焊缝硬度略低,为HV451;热影响区硬度值为HV200~HV250;采用ER308L+ER309L焊丝作为填充金属所得接头的抗拉强度略低于采用ER308L焊丝填充的接头,但其冲击韧性更好。

304/Q345 dissimilar steel were welded using lasr-MAG hybrid welding technique with two different Cr and Ni content filling metal, ER308L and ER309L. Two filling styles of ER308L+ER309L(where ER309L was used as transformed layer) and ER308L single were applied. The microstructure and mechanical properties of the joints were measured. The results showed that lower beinite, δ-ferrite and austenite could be observed in the two types of weld metal. The weld metal hardness value was the highest, the ER308 L filler weld metal reached HV489, the ER309L+ER308L weld metal hardness was slightly lower, HV451. The heat affected zone hardness value was roughly HV200~HV250. The tensile strength of the joint filled with ER308L+ER309 L was slightly lower than that of the joint filled with ER308L wire, but its impact toughness was higher.