### Title: Effect of process parameters on mechanical properties of submerged arc butt-welding experiments and statistical modelling

Authors: S. Datta, M. Sundar, A. Bandyopadhyay, G. Nandi, P.K. Pal, S.C. Roy

Addresses: Department of Mechanical Engineering, B.P. Poddar Institute of Management & Technology, 137, V.I.P. Road, Poddar Vihar, Kolkata-700052, West Bengal, India. ' School of Laser Science & Engineering, Jadavpur University, Kolkata-700032, India. ' Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, India. ' Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, India. ' Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, India. ' Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, India

Abstract: Nonlinear mathematical models were developed in order to reveal the direct and interactive effects of process parameters on mechanical properties of butt weldments by Submerged Arc Welding (SAW). Based on factorial design without replication, experiments were conducted with different levels of process parameters – welding current, electrode stick-out and voltage on mild steel plates – to obtain butt welds. Various bead quality and performance parameters like hardness, toughness, yield strength and ultimate tensile strength were measured for each of the butt welds made in the experimental runs. All of these data were utilised to develop mathematical models for the prediction of mechanical properties of the weldment for different settings of the factor level. Multiple linear regression method was used to calculate the coefficients of the models. The significance of the coefficients for each of the factors in the models was calculated by Analysis of Variance (ANOVA) Method. The predictions as given by the models have been represented graphically to show the influence of the process control parameters on bead quality in terms of mechanical properties associated with the weldment.

Keywords: submerged arc welding; SAW; factorial design; electrode stick-out; bead quality; multiple linear regression; analysis of variance; ANOVA; process parameters; mechanical properties; butt welds; statistical modelling; welding current; voltage; mild steel plates; hardness; toughness; yield strength; tensile strength.

International Journal of Microstructure and Materials Properties, 2007 Vol.2 No.3/4, pp.339 - 360

Published online: 07 Oct 2007 *