利用超窄间隙激光填丝焊技术实现了P92/Inconel 625异种接头,研究了焊接接头的组织和力学性能。结果表明,焊接接头的焊缝整齐,侧壁熔合良好,无气孔等缺陷;焊缝具有典型的凝固组织特征。P92钢热影响区的组织为马氏体,并分为粗晶区和细晶区。焊接接头界面中P92钢粗晶区的硬度最大,经热处理后硬度减小。常温拉伸试验中试样均断裂于Inconel 625合金,高温拉伸试验和高温持久试验中试样均断裂于P92钢,焊接接头的冲击韧性介于两种母材之间。

The dissimilar weldment of P92/Inconel 625 is realized by the ultra-narrow-gap laser welding with filler wire and the microstructures and mechanical properties of the welded joints are systematically investigated. The results show that the quality of the welded joints have smooth welds, nice sidewall fusion, no pores and other defects. The welds possess a typical characteristic of solidification structure. The microstructure in the heat affected zone of P92 steels is martensite, which is divided into the coarse grain and fine grain zones. The micro-hardness in the fine grain zone of P92 steel at the welded joint interface is the largest, but it decreases after heat-treatment. The specimens fracture at Inconel 625 alloy in the tensile tests at the room temperature, but fracture at P92 steel in the tensile and stress-rupture tests at high temperature. The impact toughness of welded joints is between those of the two kinds of base materials.