Determination of the Ti₂O₃-CaO-Al₂O₃ Phase Diagram at Steelmaking Temperature

Abstract

In order to make the basis of oxide inclusion study containing titanium in the calcium treated steel, Ti₂O₃-CaO-Al₂O₃ phase diagram was investigated by diffusion couple experiments and high temperature equilibrium experiments. Ti₂O₃-CaO-Al₂O₃ phase diagram has been determined at 1600°C and 1550°C, under P_O2=10_-14-10_-15 atm, which corresponds to dissolved oxygen content in deoxidized molten steel. In this system, liquid phase region, possibly forming plastic spherical inclusion, becomes narrower when Ti₂O₃ content is more than approximately 20 wt%. This region is also notably diminished when the temperature drops from 1600 to 1550°C. The reliability of the results measured in this work was confirmed by a good agreement of liquidus line and solid solubility with previous works.