Multi-objective Optimization of Welding Parameters of Pulsed Current Micro Plasma Arc Welded AISI 904L Super Austenitic Steel

Abstract

In the present work, AISI 904L super austentic steel sheets of 0.4 mm thick were butt welded using Micro Plasma Arc Welding. Welding input parameters like peak current, base current, pulse rate, and pulse width were considered, and output responses like fusion zone grain size, hardness, and ultimate tensile strength of the welded joint were evaluated. Thirty-one experiments were performed as per Central Composite Design (CCD) design matrix of Response Surface Method (RSM) by considering four factors and five levels of welding input parameters. Grey Relational Analysis (GRA) was carried out to minimize fusion zone grain size and maximize fusion zone hardness and ultimate tensile strength to find the optimal combination of welding input parameters. The order of importance of the welding input parameters was also identified, and an improvement in Grey Relational Grade was found.