Calculations of Thermodynamic Equilibrium and Al ₂ O ₃ Inclusion Nucleation in Fe–Al–O System by Integrating Different Thermodynamic Models and Classical Nucleation Theory

In recent years, high‐aluminum steels have gained significant attention due to low density and high strength. However, the thermodynamic equilibrium and nucleation behaviors of inclusions in high‐aluminum steels differ from traditional steels due to the high aluminum content. This study investigates the thermodynamic equilibrium and nucleation behavior of Al 2 O 3 inclusions in liquid iron by integrating the Wagner interaction parameter formalism, associate model, and modified quasi‐chemical reaction model (MQM) with classical nucleation theory. Under high aluminum conditions, the Al–O equilibrium calculated by the MQM model shows better agreement with the experimental data. As for the nucleation kinetics of Al 2 O 3 inclusions, the increase of interfacial tension, nucleation radius, and contact angle all makes the nucleation of Al 2 O 3 inclusions more difficult in liquid iron. The present thermodynamic model comparison and analysis of inclusions nucleation collectively contribute to the control of inclusion formation in high‐aluminum steels.