Equilibrium relationships between oxide compounds in MgO-Ti 2O 3-Al 2O 3 with iron at 1 873 K and variations in stable oxides with temperature

Abstract

It is important to determine the equilibrium relationships between the oxide compounds in MgO-Ti 2O 3- Al 2O 3 and iron to avoid Al 2O 3 or MgO·Al 2O 3 formation and for inclusion control. In this study, the equilibrium relationships between the oxide compounds in MgO-Ti 2O 3-Al 2O 3 and molten iron are investigated at 1 873 K. The phase-stability diagrams, which show the equilibrium relationships between the oxide compounds in MgO-Ti 2 O 3-Al 2O 3 and molten iron, are described. It is also important to know the oxides that newly form after solidification. Accordingly, the temperature-dependences of the stable compounds that newly form after solidification were investigated using the thermodynamic calculation software FactSage 6.1. Although the compounds formed after solidification are not necessarily the same as the equilibrium oxide compounds at 1 873 K, the correlation between them can be confirmed. In particular, under the unstable condition of MgAl 2O 4 at 1 873 K, it is found that the formation of MgAl 2O 4 could also be suppressed after solidification. © 2011 ISIJ.