Abstract
Isothermal phase relations for the Al2O3–SiO2–TiOX system have been investigated under strongly reducing conditions, achieved by equilibrium between graphite and CO gas, PO2=4.56×10-16 atm at 1873 K, in equilibria with a saturating oxide tablet.
Activities of Al2O3 and SiO2 were measured by the Knudsen effusion method. Activities of SiO2 were also measured by the chemical equilibrium between the oxide and the Fe–Si–C alloy. Activity of TiOX was also estimated from the composition of the Si–Al–Ti alloy in equilibrium with the oxide assuming that the alloy conformed to a regular solution. In addition, steel composition equilibrated with the oxide of arbitrary composition has been calculated by the activities of each component of the oxide system obtained in the present study.