A multiphysics model of the electroslag rapid remelting (ESRR) process

This paper presents a numerical model (3D) incorporating multiphysics for an electroslag rapid remelting (ESRR) process of industrial scale. The electromagnetic field is calculated in the whole system including the electrode, molten slag, ingot, graphite ring, and mold; the interaction between the turbulent flow and electromagnetic field is calculated for all fluid domains (molten slag and melt pool); the thermal field is calculated in the molten slag, ingot and mold. The solidification of the billet ingot and the formation of solid slag skin layer along the T-mold are considered as well. The formation of the skin layer adjacent to the T-mold can remarkably impact the electric current path in the whole system. The modeling result indicates that no skin layer would form on the graphite ring, as the local electric current density is very high. In contrast, a thick slag skin layer forms along the inclined part of the T-mold, blocks the electric current path there. Those modeling results are verified by experiments. A typical non-axis symmetry flow/thermal field in the slag region, which has been observed in-situ from the slag surface during operation, is predicted. Detailed analyses of the quasi-steady state results of flow/thermal fields are presented. A symmetric melt pool (profile of the solidifying mushy zone) of the ingot is predicted, which agrees with the experiments.