厚规格钢板在ACC中极限冷却速度研究

Study on Ultimate Cooling Rate During ACC of Heavy Plates

通过数值模拟方法对钢板冷却过程温度变化进行研究,分析冷却速度随换热系数的变化规律.结果表明,随着表面换热系数增大,冷却速度呈S形,逐渐达到一稳定值.随着换热系数的增大,当冷却结束时,钢板表面温度接近于冷却水温度,冷却速度达到极限值.极限冷却速度远大于加速冷却和超快速冷却的冷却速度.极限冷却速度随钢板厚度的增大、开冷温度升高和终冷温度的降低而减小.冷却水温度对极限冷却速度影响较小.

The change in temperature during plate cooling was investigated by numerical simulation to analyze how the cooling rate changes with heat transfer coefficient.The results showed that the change of cooling rate with increasing heat transfer coefficient presents an S-like curve,and then the cooling rate becomes stable gradually.With the increasing of heat transfer,when the temperature of plate surface approximates to that of cooling water at finish cooling and the ultimate cooling rate comes true.The ultimate cooling rate is far higher than the cooling rates of both accelerated cooling（ACC） and ultra fast cooling（UFC）,and it decreases with the increase in plate thickness and start cooling temperature and decrease in finish cooling temperature.However the cooling water temperature has less influence on the ultimate cooling rate.