Evaluation of Tensile Strength of a Butt-Welded Joint Considering the Effect of Welding Parameters Using Response Surface Methodology

Abstract

In this work, effect of welding parameters during metal inert gas welding (MIG) namely, welding current, flow rate of shielding gas and arc voltage is evaluated in terms of tensile and yield strength of butt-welded mild steel plates (IS 2062 Gr.E250, Quality A).MIG experiments were planned using Central Composite Rotatable Design (CCRD).Response Surface Methodology (RSM) technique was used to develop the correlations between the process variables and the responses. The correlation coefficients of developed multiple linear regression models found close to 0.9 indicate that the developed models are significant to predict the responses within the domain of process parameters selected in the present study. Study of analysis showed that ultimate tensile strength and yield strength are mostly affected by higher order of welding current and shielding gas flow rate. Results of optimization study showed that welding current of 170 ampere, shielding gas flow rate of 12 lpm (liter/min) and arc voltage of 24 V (volts) results in maximum values of tensile strength and yield strength of welded joint.