Study on arc characteristics and weld appearance of Laser-twin-arc-GTAW hybrid welding

Abstract

Laser twin-arc GTAW (LTA-GTAW) process has been developed by using the synergic interaction effects of laser and a coupled arc in a weld pool in order to achieve higher energy efficiency. In this study, bead-on-plate welding was conducted on 8-mm-think Q235b workpieces to investigate the variation of hybrid arc profile, Influence of mixed arc profile on weld forming arc, arc pressure distribution during LTA-GTAW process. The influence of Laser-GTAW and LTA-GTAW methods on weld surface appearance, heat input per unit length and weld metal microstructure were also demonstrated systematically. The LTA-GTAW can make the distribution of arc pressure and arc energy more reasonable in welding depth and width. Compared with Laser-GTAW, LTA-GTAW processes has smaller heat input per unit length, significantly finer weld microstructure and the comprehensive mechanical properties of the weld are better when the same penetration depth is achieved.