Enhancing microstructure and mechanical properties of dissimilar TIG welded duplex 2205 and Ni-based inconel 718 superalloy through post weld heat treatment

Abstract

In demanding applications, maintaining structural integrity in dissimilar welded joints like those between duplex stainless steel and Ni-based superalloys requires achieving the best possible mechanical properties. This work examines the impact of post-weld heat treatment (PWHT) on the mechanical characteristics of joints made via double-sided tungsten inert gas (TIG) welding. The dissimilar welded joint was investigated by exposing it to the PWHT for 12 h at 650 °C. Reducing the negative impact of heat generated by welding on the mechanical characteristics and microstructure of the fusion zone was the main goal. To study for changes in the microstructure before and after PWHT, optical microscopy and scanning electron microscopy methods were used for microstructural analysis. To determine the effect of PWHT on the welded joints, mechanical properties such as tensile strength, toughness, and ductility were also assessed. The mechanical properties showed significantly enhanced characteristics and refined grain structures in the fusion zone.