On melting of electrodes during electro-slag remelting

Abstract

In this paper a numerical investigations on the thermal state and on the tip shape of a melting electrode during electro-slag remelting are presented. In the first part the heat necessary to melt an electrode with a flat tip shape is calculated. It is shown that to keep a constant melting rate, the heat supplied to the electrode must be continuously changed. The results for different electrode descend rates, corresponding to different melting rates, are presented. In the second part the melting process was simulated with the help of a numerical model which takes into account simultaneous action of magneto-hydrodynamics, and thermal and phase changes phenomena. The model assumes no mould current. Simulations were performed with constant applied current and electrode descend velocity. The simulations have shown that the coupling between the melting rate and the Joule heat release process is very unstable. One result showing a stable electrode tip is presented and discussed in details. © 2014 ISIJ.