Transient Thermo-fluid and Solidification Behaviors in Continuous Casting Mold: Evolution Phenomena

摘要

A mathematical model coupling fluid flow with heat transfer as well as solidification in continuous casting mold is presented. The model features the formations of meniscus and slag films, including the growth of slag rim. Furthermore, the model describes the evolution of heat flux and thicknesses of shell and slag films from cast-start to steady-state in combination with actual operating conditions. The predictions in the developed model are in good agreement with plant measurements. The results show that a large amount of liquid slag infiltrates into the gap as the shell is withdrawn at a casting speed of 0.3 m/min, which creates the initial meniscus topography. The meniscus profile tends to bulge up at a higher casting speed, while the size of slag rim decreases. Large fluctuations of heat flux are found before forming a steady structure of slag films throughout the mold. Increasing in casting speed leads to thinner slag films and higher heat flux. This model provides a fundamental understanding on the influence of meniscus profile and slag films related to the casting speed on slab solidification, especially at the initial stage of casting process.