The mechanisms of arc coupling and rotation in cable-type welding wire CO2 welding

Abstract

In the cable-type welding wire CO2 welding process, the arc coupling and rotation behaviors are greatly different from those in typical single-wire CO2 welding. A deflection length model is proposed to explain the phenomenon of arc shape interaction and coupling, which is considered to be caused by a concentration of forces at the central wire resulting from the electromagnetic forces generated by the currents running through the individual wires. The arc rotation is influenced by the compositional characteristics of the cable-type welding wire as the wire is fed, resulting in self-rotation as the wire melts. The arc stability, the droplet transfer behavior and the weld pool are affected by the balance of the forces during the welding process and cause the arcs from the cable-type welding wire to couple together, resulting in a stable arc and stable droplet transfer. The combined forces acting on the weld pool are beneficial for the transfer of arc heat and droplet heat to the side and bottom of the molten pool, affecting the weld pool and weld formation.