On the Importance of Electric Currents Flowing directly into the Mould during an ESR Process

In the present paper a numerical model is developed to predict the exact electric current paths in the slag region of an Electro-Slag-Remelting (ESR) process. The model solves the momentum and energy equations. The solidification of the slag at the mould is modelled with an enthalpy-porosity approach. The magnitude of the Joule heating and the Lorentz force are derived from the computed electric current lines. The localization where the Joule heating occurs controls the temperature distribution. The electric current distribution is in turn influenced by the temperature field through the temperature dependant electric conductivity. With this numerical tool the electric current paths are exactly computed by choosing the less resistive way to the liquid pool, or to the mould. For a given electric intensity the model predicts the power generated by the system and the solidified slag thickness at the mould. The model is validated by comparing its results with experiments on a small scale ESR process with high current density.