Optimizing Fusion Zone Grain Size, Hardness and Tensile Strength of Pulsed Current Micro Plasma Arc Welded AISI 304 and AISI 430 dissimilar Alloy using Grey Relational Analysis

Abstract

In the present work, two dissimilar AISI 304 and AISI 430 sheets of 0.4mm thick is butt welded using Micro Plasma Arc Welding. Welding input parameters like peak current, base current, pulse rate and pulse width are considered and output responses like fusion zone grain size, hardness and ultimate tensile strength of the welded joint are considered. 31 experiments are performed as per Central Composite Design (CCD) design matrix of Response Surface Method (RSM) by considering four factors and five levels of weld input parameters. Grey Relational Analysis (GRA) is carried out by minimizing fusion zone grain size and maximizing fusion zone hardness and ultimate tensile strength to find the optimal combination of weld input parameters. The order of importance of weld input parameters are also identified and improvement in Grey Relational Grade was found.