Numerical analysis of arc and droplet behaviors in gas metal arc welding with external compound magnetic field

A self-designed external compound magnetic field assisted gas metal arc welding process was developed to suppress the weld bead defects in high-speed welding. A comprehensive numerical model containing the arc and filler metal was proposed to investigate the influence of the external compound magnetic field on the arc and droplet behaviors. The external magnetic field caused the arc and filler metal to incline forward continuously along the welding direction as well as swinging periodically perpendicular to the welding direction. And the external magnetic field increased the metal transfer frequency and decreased the size of the droplet. The external electromagnetic force caused the inclination of the arc and then the arc inclination changed the arc plasma force acting on filler metal. The change of arc plasma force has greater influence on the droplet inclination and metal transfer frequency than the external electromagnetic force.