ABSTRACT

Dissimilar welding potentially has great importance for many industries. Joining of two different alloys is very challenging. In this paper, an attempt was made to produce a reliable joint between Nickel-based superalloy with stainless steel using the gas tungsten arc welding process with nickel-based filler wire. Post-weld heat treatment was executed at 700°C for 2 h. A critical comparison was made between the post-weld heat-treated samples and as-welded samples. The tensile test indicates that the strength of the joint is higher than the weaker base metal (Stainless Steel). The macrostructure and microstructure show proper fusion and bonding among the parent metals and filler wire. There is a formation of the partially melted zone at fusion boundary and secondary phase (Niobium-rich phase) at a region adjacent to the fusion boundary on heat-affected zone of Inconel side. It was also observed that the post-weld heat-treated samples have a significant reduction in the secondary phase. Vickers’ microhardness value indicates that the secondary phase has a higher value of hardness both in as-weld condition and post-weld heat treatment condition. Thus, Nickel-based filler wire is a compatible filler wire for the dissimilar joint.

摘要

异种焊接可能对许多行业都具有重要意义。两种不同合金的连接非常具有挑战性。在本文中，尝试使用带有镍基填充焊丝的钨极气体保护焊工艺在镍基高温合金与不锈钢之间制造可靠的接头。焊后热处理在 700°C 下进行 2 小时。对焊后热处理样品和焊后样品进行了严格的比较。拉伸试验表明接头的强度高于较弱的母材（不锈钢）。宏观结构和微观结构表明母材和填充焊丝之间有适当的熔合和结合。Inconel侧的热影响区靠近熔合边界的区域形成了部分熔化区和第二相（富铌相）。还观察到焊后热处理样品的第二相显着减少。维氏显微硬度值表明第二相在焊态和焊后热处理条件下均具有较高的硬度值。因此，镍基填充焊丝是异种接头的兼容填充焊丝。