Numerical simulations of arc plasma under external magnetic field-assisted gas metal arc welding

The arc plasma behavior for gas metal arc welding (GMAW) with an external compound magnetic field was numerically investigated. A three-dimensional finite element model for the external magnetic field (EMF) and a three-dimensional finite volume model for the arc plasma were established. The effects of the EMF on the redistribution of the temperature, fluid flow, pressure, and electromagnetic force in the arc plasma were compared with traditional GMAW under the same welding parameters. The control mechanism of the external compound magnetic field on the arc plasma behavior was analyzed. The results show that the magnitude of the additional electromagnetic force was much lower than that of the self-induced electromagnetic force, but it caused forward inclination and periodic swinging of the arc plasma. When an EMF was applied, the peak temperature decreased, and the temperature distribution was more uniform. The peak pressure was also much smaller than that without an applied EMF.