Abstract: Physical modeling was employed to investigate the effects of ladle change time, casting speed, and turbulence inhibitor on slag movement and exposure behavior in a tundish during continuous casting of non-oriented silicon steels. The effect of the slag carry-over on slag entrainment in the tundish was also studied. Results show that there was a serious slag entrainment phenomenon in the impact zone during ladle change when the refilling time was 69 s and the turbulence inhibitor was not used. As the refilling time increased, the slag entrainment phenomenon was lowered and part of the top surface of the impact zone was exposed, indicating that reoxidation easily occurred under the current conditions. Increasing the casting speed increased the amount of entrained oil phase in the impact zone during ladle change. It would decrease the steel cleanliness. The installation of the turbulence inhibitor significantly decreased the amount of entrained oil phase and the exposed area in the impact zone during ladle change. It was suggested that the turbulence inhibitor should be used in the impact zone and the refilling time was larger than 180 s. According to the slag carry-over experiments, the adverse effect of the slag carry-over on the steel cleanliness could not be completely eliminated using the turbulence inhibitor and it could only diminish the slag entrainment and emulsification. The entrained slag might be a source of exogenous inclusions in the final product. Therefore, the slag carry-over from the teeming ladle should be strictly controlled during the actual casting process.

Key words: continuous casting tundish, slag entrainment, ladle change time, casting speed, turbulence inhibitor, physical modeling