| Abstract Scope |
With increasing demands for high-performance steel, the control of non-metallic inclusions has become critical. MnO-TiOx-based oxides are known to promote intragranular ferrite formation, enhancing toughness. However, under strong deoxidation conditions, MnO is often reduced, potentially altering the composition of the oxides. Therefore, this study focuses on Al₂O₃-SiO₂-TiOx-based inclusions, which are expected to remain stable under such conditions.
We systematically investigated the phase equilibria and thermodynamic activities in the Al₂O₃-SiO₂-TiOx system at 1873 K. Phase relations were determined using equilibrium experiments with oxide pellets and molten alloys. Activities of SiO₂ and Al₂O₃ were quantified using Knudsen cell mass spectrometry.
Additionally, the interaction parameter between Si and Ti in molten iron was evaluated. Using the obtained thermodynamic data, we established a method to predict steel chemistries in equilibrium with target inclusions.
Furthermore, a low-reactivity tundish flux was developed to suppress changes in steel cleanliness. |