Impact of Weld Time and Solution Treatment on the Performance of IN625 Spot Joints: An Experimental Study

This paper investigates the influence of post-weld heat treatment (PWHT) on the mechanical properties of resistance spot welding (RSW) joints in Inconel 625 (IN625). Nickel-based alloys, particularly IN625, play a crucial role in industries where superior mechanical properties are essential at a high temperature. The experimental approach involves heat treating the welded samples to a temperature of 950 °C for 1 h. The study reveals that due to the PWHT, the load-bearing capacity (LBC) and tensile-shear strength of the welded specimen are reduced drastically up to ~ 26.5% and ~ 27%. However, a noteworthy improvement in yield stress and ductility is observed by ~ 21% and ~ 20.4%, respectively. This could be attributed to the dissolution of secondary phases and the recrystallization of the nugget microstructure at higher temperatures, which directly impacts the joint strength of the welded joint. The findings of this research contribute valuable insights into optimizing PWHT processes to enhance the mechanical properties of the joints.