Kinetic Prediction for the Composition of Inclusions in the Molten Steel During the Electroslag Remelting

A mathematical model coupled with the penetration theory, the ion and molecule coexistence theory, and thermodynamic equilibrium was proposed for predicting the composition evolution of inclusions in the molten steel during the electroslag remelting process. The model was used to evaluate the transformation of composition of inclusions in a plain carbon steel and the mechanism of the transformation of inclusions was accurately revealed, which was mainly the mass transfer of aluminum through steel/slag reactions. The rate of the transformation of inclusions composition was the lowest in the metal pool, while that in the slag pool was the fastest which was due to the acceleration of reactions by higher temperature and faster fluid flow. Inclusions with smaller diameter had faster transformation rate, but had less content of Al₂O₃ in the final composition. The size of droplet showed little influence on the transformation of composition of inclusions. When the content of Al₂O₃ in the slag increased from 20 to 50 wt pct, the calculated content of Al₂O₃ in the final inclusions increased from 79 to 90 wt pct, approximately. The low content of Al₂O₃ in the slag was beneficial to the removal of aluminum in the steel, while the high content of Al₂O₃ in the slag increased the content of total aluminum in the steel.