2010 Volume 50 Issue 12 Pages 1955-1958
It is important to determine the equilibrium relationship between the oxide compounds in MgO–Al2O3–Ti2O3 and molten iron to avoid Al2O3 or MgO·Al2O3 formation and for inclusion control. In this study, we investigated the formation conditions of MgTi2O4 in preference to MgAl2O4 at 1873 K. The phase stability regions of MgTi2O4 and MgAl2O4 or Ti2O3 were determined at 1873 K in MgO–Al2O3–Ti2O3. At a low titanium content of less than 0.1 mass% and when [mass ppm Mg]=3, MgAl2O4 forms at more than [mass%Al]=0.08 and the region of MgAl2O4 formation widens as the titanium content of the molten iron decreases. Accordingly, it is necessary to lower the Al content and to adjust the Ti content to an appropriate concentration range to form MgTi2O4 instead of MgAl2O4.