Optimization of Temperature Distribution in Thick Slab Continuous Casting for Direct Hot Rolling

摘要

In order to predict and control the exit temperature of continuous casting slab before the down-stream direct rolling process, a three-dimensional model for the heat transfer and solidification during continuous casting has been developed based on the realistic roller-diagram and spray nozzle arrangement. Both heat transfer properties and flux distribution of the nozzle spray on the slab were considered, and the complicated boundary conditions, such as spray cooling, natural convection, thermal radiation as well as contact cooling of individual rolls were involved in the model. By calibrating the caster dependent model factor, the calculated temperature and solidification end accorded with the practice. An example of modifying the thick slab temperature at the caster exit before the hot rolling showed that the slab temperature at the caster exit was effectively improved by decreasing the spray cooling water at the last loop of the secondary cooling zone, raising the casting speed and decreasing the pouring temperature, which satisfied the requirement of the continuous casting and direct rolling.