Optimal conditions of friction welding process for AISI 1015 steel using response surface methodology

Abstract

      The purpose of this research was to determine the relationship between various important parameters of the friction welding process for AISI 1015 steel to obtain a maximum tensile strength of welding joints. In this study, response surface methodology (RSM) was employed to evaluate the effects of friction time, upset time, friction pressure, upset pressure and rotational speed on the tensile strength of welding joints. The results from the RSM analysis indicate that the friction time, friction pressure and upset pressure have the most significant effect on tensile strength of welding joints, while the upset time and rotational speed were not significant. The coefficient of determination (R²) of the mathematical model was 0.8064. The optimal conditions of friction welding, which obtained the maximum tensile strength of welding joints of 1048 MPa, were performed at friction time of 8.86 sec, upset time of 2.22 sec, friction pressure of 29.36 bar, upset pressure of 59.25 bar and rotational speed of 1259.58 rpm. The experimental values of the optimized condition exhibited tensile strength of welding joints of 1007 MPa. Comparison of the experimental values with those of the predicted values was almost identical with low percentage bias of tensile strength of welding joints of 3.91%. Therefore, the mathematical model has developed adequately describing ranges of the experimental parameters studied and provides a statistically accurate prediction of the optimum tensile strength of welding joints.