A Comprehensive Mathematical Model of Electroslag Remelting with Two Series-Connected Electrodes Based on Sequential Coupling Simulation Method

A comprehensive mathematical model of electroslag remelting with two series-connected electrodes (TSCE-ESR) was constructed based on sequential coupling method. The influence of droplet effect on electroslag remelting process (ESR) was considered in this model. Compared with one-electrode electroslag remelting (OE-ESR), the multi-physics field, droplet formation and dripping behavior, and molten metal pool structure of TSCE-ESR process were studied. The results show that during the process of TSCE-ESR, the proximity effect of the electrodes suppresses the skin effect, and Joule heat is concentrated in the area between the two electrodes of slag pool, making the temperature distribution of the slag pool more uniform. The heat used to melt the electrode in the process of TSCE-ESR accounts for about 34% of the total Joule heat, which is lower than the OE-ESR (17%). Therefore, it makes a higher melting rate and a smaller droplet size in the process of TSCE-ESR. Compared with OE-ESR, TSCE-ESR process can realize the unification of higher melting rate and shallow flat molten metal pool. Compared with the results without droplet effect, it is found that in the simulation results with droplet effect, the depth and the cylindrical section of molten metal pool increased, and the width of the mushy zone is significantly reduced, which is more consistent with the actual electroslag remelting process.

Numerical Simulation of Electroslag Remelting Process for Producing GH4169 under Different Current Frequency

A comprehensive analysis of the physical processes that occur in Electroslag Remelting (ESR) process under steady state conditions and axisymmetric was performed using the simulation software MeltFlow. The detailed plots of current distribution, volumetric heating, flow, temperature and turbulent mixing provide insight into the various physical phenomena that occur in ESR process. The effect of current frequency on various physical fields was analyzed. It is shown that, the current in the slag tends to become more uniform due to the low electrical conductivity of the slag; after the current enters the ingot, the skin effect increases with the increase of the current frequency; the Joule heating and the Lorentz force are highest near the tip of the electrode in the slag, and increase with the increase of the current frequency; the velocities in the slag are slightly higher than those in the molten metal pool; with the increase of the current frequency, the liquidus temperature moves down, and the molten metal pool is deepened. Simulation results agree well with experimental results. Therefore, the generation and extent of defects could be predicted in different process.