Numerical Analysis on the Multi-Physics Field in the ESR System with Vibrating Electrode

The electroslag remelting (ESR) process has been used widely to produce large ingots of high quality based on the controlled solidification and chemical refining that can be achieved. The vibrating electrode method was used in the ESR process in this paper, which can improve the quality of solidification and reduce the energy consumption. A transient three-dimensional (3D) coupled mathematical model was developed to simulate the electromagnetic phenomenon, fluid flow as well as pool shape in the ESR process with vibrating electrode. The finite element volume method is developed to solve the electromagnetic field using mechanical APDL software. Moreover, the electromagnetic force and Joule heating are interpolated as the source term of the momentum and energy equations. The flow field, temperature profiles and pool shapes are demonstrated by the finite volume model of FLUENT software. The volume of fluid (VOF) approach is implemented for the two-phase flow. The solidification of metal is simulated by an enthalpy-porosity formulation. The multi-physical fields have been investigated and compared between the traditional electrode and the vibrating electrode in the ESR process. The results show that the behavior of metal droplets with traditional electrode is scattered randomly. However, the behavior of metal droplets with vibrating electrode is periodic. The maximum temperature of slag layer with vibrating electrode is higher than that with traditional electrode, which can increase the melting rate as to the enhanced heat transfer in the vicinity of the electrode tip. The parameters study show that when the amplitude and frequency of vibrating electrode increases, the cycle of behavior of metal droplets decreases significantly.