Effect of electrical parameters and slag system on macrostructure of electroslag ingot

To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting, different power supply modes, current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel, and the macrostructure of electroslag ingots was analyzed. The results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply mode. The effects of different power supply modes, such as low-frequency, direct current straight polarity (DCSP), and direct current reverse polarity (DCRP), on reducing the depth of the metal pool increase in that order. By reducing the remelting current strength in the same power supply mode, the depth of metal pool is reduced. When compared to the binary slag system of 70% CaF2+30% Al2O3, the ternary slag system of 60% CaF2+20% Al2O3+20% CaO is more effective in reducing the depth of the metal pool during remelting. Utilizing the 60% CaF2+20% Al2O3+20% CaO ternary slag system results in a shallower and flatter metal pool, with columnar crystal growth occurring closer to the axial crystal. This effect is observed for both low frequency and direct current (DC) power supply modes.