The Design of Slag and Electroslag Remelting Production Technology of Steel Containing Zirconium

Slag–metal reaction experiments in MoSi2 resistance furnace combined with electroslag remelting (ESR) experiments in ESR furnace are used to study the effect of slag on zirconium distribution in ESR ingot by establishing a new mass transfer model of slag–metal reaction. The mass transfer model consists of Al + Al2O3, Si + SiO2, Zr + ZrO2, and Fe + FeO systems based on the penetration and film theories. Both experimental and simulated results show that the returned slag (CaF2:CaO:Al2O3:MgO:ZrO2 = 57:20:16:3:3) combined with extra 4% Al2O3 added into molten slag in the first slag-temperature-rising period can control the zirconium in ESR ingot ranging from 0.35 to 0.40% and improve the homogeneous distribution of zirconium in ESR ingot. The returned slag of Exp.A containing low silica being used in Exp.C can not only contribute to the recycling of returned slag, but also improve the homogeneous distribution of Zr along the height of ESR ingot.