A reaction model was developed to better understand the evolution of inclusions in Al–Ti-killed steels during the ladle mixing process. The fluctuation of steel chemistry gave rise to the transient evolution of inclusions during the mixing process. The formed Al2O3 in the steel can be hardly influenced by the addition of FeTi, while adding Al can effectively modify the TiOx-containing oxides to solid Al2O3. The formation of Al2O3–TiOx inclusions can be suppressed by increasing Al and lowering Ti in the steel. The alloying sequence of adding Ti after the Al addition is beneficial to improve the recovery of Ti. The one-point strong air absorption may cause the formation of the unwanted Al2O3–TiOx inclusions in Al–Ti-killed steels. The critical oxygen contents in the molten steel with varying Al and Ti concentrations were predicted to avoid the formation of Al2O3–TiOx inclusions and Ti loss.
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