Double arc interference and dynamic behavior characteristics of double wire double-pulsed GMAW

Abstract

The double wire gas metal arc welding (GMAW) technology combined with double pulse low-frequency modulation offers the benefits of the higher efficiency of double wire GMAW combined with superior weld joint quality offered by double pulse low-frequency modulation. However, the potential for severe double arc interference of double wire double-pulsed GMAW affects the stability of the welding process and has thus far limited its widespread use. In this study, high-speed photography was used to record the arc profiles and arc interference of double wire double-pulsed GMAW in the synchronous and alternant phases, while the voltage and current waveforms were simultaneously recorded. Experimental results demonstrated that the double arc deflection of the strong pulse was more severe than that of the weak pulse due to the high current associated with a strong pulse. It was also discovered that the trailing arc stiffness was lower than the leading arc stiffness. Moreover, the deflection of trailing arc was greater under the influence of the leading arc’s electromagnetic attraction. Whereas, the arc deflection of the pulse stage in the alternant phase was small, less than that of the pulse stage in the synchronous phase, the arc deflection of the background stage was much greater. Furthermore, the arc deflections of the pulse and background stages in the synchronous phase were smaller than the arc deflection of the background stage in the alternant phase. Finally, the leading and in the synchronous phase maintained their stiffness and demonstrated weaker magnetic arc blow, fewer spatters, a more refined fish-scale appearance, and weld beads with better uniformity.