Corrosion of alumina-magnesia castable by high manganese steel with respect to steel cleanness

Abstract

High manganese steel has been widely used in the national defense, automobile and petrochemical industry fields due to its excellent wear resistance and low temperature toughness. Alumina-magnesia refractory plays a significant role in high manganese steel smelting. In this paper, the interaction between alumina-magnesia castable and high manganese steel, and its effects on the quality of high manganese steel were analysed. The Fe and Mn of the molten steel transferred into the castable during the early smelting stage, so a reacted metamorphic layer with lower melting point was formed between the refractory castable and high manganese steel. With the prolongation of smelting time, the thickness of the reaction layer and number of molten steel droplets entrained into the refractory castable-high manganese steel reaction layer were increased under dynamic conditions. Some refractory particles were loosed and dropped into the reaction layer, which accelerated the erosion of the refractory castable, causing an increase in the total [O] content in the steel. An isolation layer of (Fe, Mg, Mn)Al2O4 composites began to form after 30 min and the total [O] content in the steel decreased gradually to below 10 ppm after 60 min. The formation of an isolation layer prevented the corrosion of the refractory castable and guaranteed steel cleanness within 90 min of smelting, but resulted in a 2% decrease of the Mn content in the high manganese steel during the smelting process.