Reaction behavior of MgO refractory with high-Mn and high-Al steel

To understand the mechanism of the interfacial reaction between high-Mn and high-Al steel and MgO refractory, a series of laboratory experiments as well as thermodynamic calculations were performed. The effects of Mn and Al contents in the steel and the reaction time on the interfacial reaction were investigated. It was observed that the erosion of the MgO refractory is caused by the reaction of Al and Mn in the steel with MgO in the refractory, which would lead to the formation of (Mn, Mg)O<middle dot>Al2O3 spinel and (Mn, Mg)O solid solution. The formation mechanism of the spinel and solid solution is as follows. The Al in the steel firstly reacts with MgO in the refractory to generate MgO<middle dot>Al2O3 spinel, and then, the spinel reacts with Mn in the steel to form (Mn, Mg)O<middle dot>Al2O3 spinel. Finally, the MnO in the spinel reacts with the MgO in the inner refractory to form (Mn, Mg)O solid solution. In addition, only (Mn, Mg)O<middle dot>Al2O3 spinel is present in the interfacial reaction layer of the refractory when the Al content in the steel is sufficient.