Simulation study of thermal transfer characteristics in the twin-electrode electroslag remelting process based on ProCAST

Abstract

The twin-electrode electroslag remelting (TE-ESR) process is widely used in the production of high-value-added alloys. The process is conducted in an enclosed environment comprising a crystalliser, a bottom water tank, furnace slag, and electrodes. In this study, the ProCAST simulation software was used to establish a three-dimensional temperature field for the entire TE-ESR process of M42 high-speed ingot with a diameter of 360 mm. The model employs the mixed Lagrangian–Eulerian algorithm to simulate the continuous growth of remelted ingots and simulates the pouring of molten droplets by setting INLET gates. Among these processes, electrode melting, increase in the ingot height, and rise of the slag were simulated by setting relative motion between the crystalliser and water box at the bottom, ultimately obtaining the temperature field of the entire TE-ESR process. Direct comparisons were made between the metal melt pool depths obtained from experiments and numerical simulations, and the cooling rates were indirectly contrasted by comparing the distances between ledeburite network lattices at different characteristic points, thereby validating the reliability and accuracy of the numerical model. Based on the proposed model, the effects of the electrode melting temperature (initial temperature of the metal melt pool) and heat transfer intensity of the water-cooled bottom plate on the temperature field were simulated and studied. By fitting the variation in the metal melt pool depth with the melting time to a Gaussian function, it was found that reducing the electrode melting temperature effectively decreased its depth. Moreover, when the ingot height was lower, increasing the heat transfer coefficient of the water-cooled bottom plate could effectively reduce the depth of the metal melt pool. These findings will help engineers to gain a comprehensive understanding of the temperature-field changes during the TE-ESR process.