Development of Predictive Model for Quality Output of Welding Process of Steel NST 37-2 Using Response Surface Methodology

Abstract

The present study investigated the effect of operating parameters in modeling the output quality of welding process of steel sample. A three factor, three levels Box-Behnken Design (BBD) of RSM was applied to determine the effects of three independent variables (welding speed (A), welding current (B) and electrode potential (C)) on the tensile strength and to also develop a model for predicting the output quality. Data analysis shows that A, C, AB, BC, A2, B2and C2are the terms which significantly affected the ultimate tensile strength of the sample at 95% confidence level. The experimental values were very close to the predicted values and were not statistically different at p<0.05. The maximum tensile strength of 228 MPa was obtained at 250 A current, electrode diameter of 3.25 mm and 50 cm/min welding speed, respectively. The regression model obtained has provided a basis for selecting optimum process parameters for the improving output quality (tensile strength) of the welded steel sample.