Application of Response Surface Method in Studying the Properties of Micro-plasma Arc Welded AISI 904L Super Austenitic Steel

Abstract

Super austenitic steels play a major role in fabrication of corrosion resistance components which are subjected to severe corrosion. In the present work, super austenitic steel AISI 904L of 0.4 mm thickness 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) matrix of Response Surface Method (RSM) by considering four factors and five levels of weld input parameters. Main plots are drawn to understand the variation of output responses with variation of weld input parameters. Mathematical models are developed using MINITAB software considering linear function. Analysis of Variance (ANOVA) is carried out at 95% confidence level. Contour plots are drawn to identify the dominating welding parameter and surface plots are drawn to find the optimal combination of input parameters.