Study on High‐Temperature Reactions of MgO Refractory with Ti‐Bearing Al‐Killed Steel

Abstract

To understand the interaction behaviors between MgO refractory and Ti‐bearing Al‐killed steel grades, laboratory experiments are conducted at different times using different steel grades containing different Ti contents (w[Ti] = 0–0.2%). The results show that when MgO refractory reacts with Ti‐free Al‐killed steel, an MgO–Al2O3 spinel‐reacted layer can be detected at the steel‐refractory boundary. In the case of Ti‐bearing Al‐killed steel, an MgO–Al2O3–TiOx system‐reacted layer is formed at the edge of MgO refractory, and the thickness of the layer and the TiOx content in the layer increase with the increase of reaction time and the dissolved Ti content in steel. Thermodynamic calculations indicate that the MgO–Al2O3–TiOx system layer is a spinel solid solution, and is the stable phase in Ti‐bearing Al‐killed steel. In addition, the melting point of the reacted layer declines with the increase of TiOx. Therefore, the corrosion of MgO refractory by Ti‐bearing steel grades is more serious than that by conventional steel grades, and it also leads to the formation of MgO–Al2O3–TiOx system macroinclusions in steel.