The Secondary Cooling Technology of Billet During High-efficiency Continuous Casting

摘要

In this paper the mathematical model of high-efficiency continuous casting of billet is developed. The concepts are put forward for the effective spraying water coefficient and the effective specific water flowrate of secondary cooling. According to the idea of uniform cooling in secondary cooling zone, the spraying cooling structure and the disposal of nozzles are redesigned and optimized, and one spraying cooling zone is increased. A new secondary cooling model of spraying water i.e., Q_i = a+ bv+ cv~2 + d(ΔT-30) + F is developed. The research points out that the spraying water flowrate of each cooling zone is related with the casting speed, the casting temperature, the contents of liquid steel, the cooling water temperature of secondary cooling. The commercial run of the caster has proved that the spraying cooling structure and the new secondary cooling model are suitable, and the casting speed is enhanced in great extent. The highest casting speed is up to 3.8-4.0m/min for the billet of section 150 x 150 mm~2. The billet quality is marked improved, and the output is marked increased. The economical benefit is greatly heightened.