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.

Effects of Metal Droplets on Electromagnetic Field, Fluid Flow and Temperature Field in Electroslag Remelting Process

“…15,16) Kharicha et al solved the electromagnetic field with electric potential method coupled with a VOF model to track the motion of metal droplets and phase boundaries, and concluded that the highest magnetic field intensity appears at the surface of droplets. 17) Wang et al developed a laboratory scale 3D multiphase-magneto-hydrodynamic model considering the effect of metal droplets on electromagnetic field, [18][19][20][21] and studied the multiphase flow and solidification in ESR process. Glesselmann et al studied the movement of droplets and solidification process using coupled multi zone models, which were solved with different time steps.…”

“…Additionally, the exposed slag surface and mould wall are assumed to be insulated excepted the electrode tip where the flux of electric potential is described. 17) The bottom boundaries and top boundaries share the identical magnetic field boundary condition, a magnetic induction flux of zero. The axial component of magnetic vector potential flux is prescribed at the mould wall, 16) where the radial component takes the value of zero.…”

Visualization Study on the Droplet Evolution Behaviors in Electroslag Remelting Process by Superimposing a Transverse Static Magnetic Field

“…Most of the simulations [15][16][17][18][19][20][21][22][23][24][25] are focused on the analysis of the electromagnetic field, temperature distribution, flow pattern and profile of the metal pool. Their researches make people know the ESR process better, and then the ESR process may be improved by controlling the temperature distribution or the flow pattern to gain a better metal pool shape which will seriously affect the quantity of ingots.…”

A Dynamic Mesh-Based Approach to Model Melting and Shape of an ESR Electrode

“…Recently, Kharicha et al [20] directly simulated the melting of electrode using the multiphase volume of fluid (VOF) method considering complex interactions between flow, temperature, and magnetic fields. It is found that the coupling between the Joule heat release and melting rate is very unstable.…”