Numerical Simulation on the Oxidation of Lanthanum During the Electroslag Remelting Process

A transient 3D mathematical model was developed to simulate oxidation of lanthanum during the electroslag remelting process, by which the electromagnetic field, fluid flow, heat transfer, and mass transfer were fully coupled via user-defined function. The formation and motion of droplets in the slag disturbed the distribution of the electric current density as well as the distribution of Joule heat and electromagnetic force, which had an influence on the motion of droplets in turn. The maximum of Joule heat, current density, electromagnetic force, and velocity increased with droplets falling, and it reached its peak when droplets departed from the electrode. The rare earth element La in droplets was continuously oxidized during droplets falling through the slag, and the yield of La was 37.5% at the bottom of the ingot, while the experimental yield was 33.3%.