Parameters optimization of tungsten inert gas welding process on 304L stainless steel using grey based Taguchi method

Abstract

Tungsten inert gas can be used to weld stainless steel due to its offering sound weld, narrow fusion zone, precise control weld’s shape and over penetration, spatter free, slagless, stable arc and low electrode wear. The goal of this study was to offer the best process parameters for improving the mechanical characteristics of the weld joint. The experimental analysis approach was applied in this work, and the experiment was carried out on 304L stainless steel using L16. The selected welding parameters were welding travel speed, current of welding, gas flow rate, arc length, and root gap. Rockwell hardness, tensile strength, and bending strength tests were the examined mechanical properties on the weld joint. Based on the grey based Taguchi method, the optimal level-settings of welding travel speed, current of welding, flow rate of gas, arc length, and root gap were obtained 2.7 mm s−1, 160 A, 14 l min−1, 3 mm, and 1 mm, respectively. The analysis result of ANOVA showed that the current has the greatest impact and it was followed by travel speed and root gap on weld joint quality with percentage contribution of 80.77%, 10.86%, and 5.98%, respectively. According to confirmation results, the average grey relational grade of 0.863 which was found between the confidence interval of 0.800 to 1.082 for the 95% confidence level, and the maximum Rockwell hardness, tensile strength and bending strength were obtained 101.38 HRB, 1425.8 MPa and 1648.6 MPa, respectively.