Effect of process parameters on double pulse metal inert gas welded joints of Inconel 718 superalloy

This work investigates the weldability of Inconel 718 plates using the double pulse metal inert gas (DPMIG) welding process. DPMIG is a special technique for managing the structure and qualities of welds because it offers a flexible and effective way to manage the temporal variation of weld pool geometry, cooling rate, and solidification parameters. Welding parameters such as wire feed rate (m/min), arc length (mm), and delta wire feed rate (m/min) are chosen to explore their impacts on the size and appearance of the weld bead of the Inconel 718 alloy, and the principles of their effects are outlined. In-depth analyses of the butt joint’s microstructure, mechanical properties, and fracture characteristics were analyzed in order to confirm the validity of this innovative procedure for welding Inconel 718 alloy. From the outcome of the investigation, the microstructure was homogenous, and ultimate tensile strength (UTS) was better, which is up to 66% of the base metal. The presence of secondary phases on the welded joints exhibits a mixed mode of fracture at the weld zone with a ripping cleavage pattern and microvoids.