Metal transfer process and properties of double-wire double pulsed gas metal arc welding

Abstract

Metal transfer processes during double-wire double pulsed gas metal arc welding (DP-GMAW) were observed in both the double pulse synchronous (DPS) and double pulse alternating (DPA) phases using a high-speed digital camera. Meanwhile, the corresponding waveforms were acquired. The results showed that metal transfer occurred as one drop per pulse (ODPP) during both the strong and weak pulse periods, irrespective of phase. In the DPA phase, ODPP was achieved more easily compared with the DPS phase and the metal transfer stability was improved. The droplet offset distance was shorter in the DPA phase. Moreover, the desirable fish-scale appearance was more evident on surface of the weld bead created in the DPA phase. Finally, penetration achieved in the DPA phase was significantly deeper, and fluctuations in the penetration were clearly observed in longitudinal section of the weld bead.