Flow and heat transfer of liquid slag in a continuous casting mold

Abstract

A three-dimensional mathematical model for coupled liquid steel and liquid slag was established to study the flow and heat transfer behavior of liquid slag. Based on the volume of fluid method and the heat transfer model, the effect of different casting parameters on the flow and heat transfer of the liquid slag was investigated. The results show that there are two different size recirculation zones of the liquid slag layer on the liquid steel in the mold center plane, extending from the submerged entry nozzle to the mold narrow face. With the increase in the casting speed and the decrease in the viscosity of the mold flux, the overall velocity and the temperature of the liquid slag increase. With the increase in the inclination angle and the submergence depth of the submerged entry nozzle, the temperature of the liquid slag decreases, and the velocity decreases near the mold narrow face and increases in the vicinity of the submerged entry nozzle. The inactive flow field and the low temperature of liquid slag within 100 mm of the submerged entry nozzle may intensify the surface longitudinal cracking sensitivity of the slab. When the lubrication and heat transfer are well regulated between the surface of mold and the mold flux film, low casting speed, large inclination angle and submergence depth of the submerged entry nozzle are beneficial for reducing the possibility of a slab surface longitudinal crack.