Reassessment of Oxide Stability Diagram in the Fe-Al-Ti-O System

Phase equilibria of Fe-Al-Ti-O system is shortly reviewed, in particular for stability of oxide phases in equilibrium with liquid Fe alloy in dilute concentration. This system is relevant to Ultra Low Carbon steel with Ti alloying (Ti-ULC), often causing clogging of Submerged Entry Nozzle (SEN) during continuous casting. In order to predict stable oxides in the Ti-ULC steel, thermodynamic calculation using CALPHAD approach was employed. Previously available thermodynamic calculations were examined, and compared with available experimental data. A slight modification of thermodynamic modeling of previous investigation resulted in noticeable improvement for the prediction of stable phases by thermodynamic calculation. Significance of the present revision of the thermodynamic modeling is discussed in the view of nozzle clogging of Ti-ULC casting.