Identification of MAG welding metal droplet transfer patterns based on features of input power

Abstract

An experimental platform was built for simultaneous acquisition of the input and output electrical signals as well as droplet transfer images during the welding process. By analyzing the rectifier circuit of the welder, the calculation method of the instantaneous input power, the instantaneous input power envelope, and the input pulsating energy (EP) were given. The input pulsating energy was found to better characterize the dynamical change process at the output terminal upon comparison. Then, the short circuiting transfer, free transfer and mixed transfer patterns were obtained by varying the wire feeding speed and the given voltage. Based on the standard variance (SD) and coefficient of variation of the input pulsating energy (v(Ep)), the parameter variations in different transition patterns and the stability of the transition process were compared and analyzed. The results reveal that the v(Ep) was greater than 18% for short circuiting transfer and less than 9% for free transfer.