Effects of electrode configuration on electroslag remelting process of M2 high-speed steel ingot

The electrode configuration determines the thermophysical field during the electroslag remelting (ESR) process and affects the final microstructure of the ingot In this work, ingot with a diameter of 400 mm was prepared with two electrode configuration modes of single power ESR process, namely one electrode (OE) and two series-connected electrodes (TSCE). Finite element simulation was employed to calculate the electromagnetic field, flow field and temperature field of the ESR system. The results show that the temperature of the slag pool and the metal pool of the TSCE process is lower and more uniform than that of the OE process. The calculated temperature distribution of the ingot could be indirectly verified from the shape of the metal pool by the experiment. The experimental results show that the depth of the metal pool in the OE ingot is about 160 mm, while the depth of the TSCE ingot is nearly 40 mm shallower than that of the OE ingot. Microstructural comparisons indicate that coarse eutectic carbides are formed in the center of the OE ingot, whereas more even eutectic carbides appear in the center of the TSCE ingot. In general, compared with the OE process, the TSCE process is preferred to remelt high speed steel ingots.