The influence of bypass current on arc energy density and metal transfer behaviour in bypass current compressed gas metal arc welding

A new welding method, bypass current compressed gas metal arc welding (BCC-GMAW), was developed to enhance the arc energy density and welding stability of GMAW. When the bypass current was applied, the arc energy density was increased with the constraining effect of the circumferential bypass electrode, which was studied by current density and arc pressure, resulting in an increase of 46% in weld depth and a decrease of 38% in weld width. As the coupled arc increased the melting speed of wire and forces of droplet downward transfer, the droplet transfer frequency increased by 185%, and the metal transfer mode was changed from short-circuit transfer to stable small globule transfer, obtaining a smooth and uniform weld appearance.