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讨论了连铸传热数学模型中等效导热系数对模拟结果的影响,结论表明,采用等效导热系数法可以较为准确的预测铸坯表面温度及凝固终点,但等效导热系数越大,凝固前期的铸坯坯壳厚度越薄;等效导热系数的取值对铸坯两相区将产生较大影响,等效导热系数越大,某一厚度处钢液越早进入两相区,相应地,两相区厚度越大、两相区内温度梯度越小,局部凝固时间越大;采用计算获得的二次枝晶间距与实测值强制拟合的方法可以获得对流等效因子(m)的合理取值;对于铸机,在液相穴中强制对流区取m=7、强制对流与自然对流的过渡区取m=5、自然对流区取m=3、静滞区取m=1计算,可以获得较为准确的模拟结果。
The effects of equivalent thermal conductivity on the simulation results are discussed. The results show that the equivalent thermal conductivity method can predict the slab surface temperature and the solidification end point more accurately. However, the larger the equivalent thermal conductivity, The thickness of the billet shell is thinner; the equivalent thermal conductivity value will have a greater impact on the billet two-phase region, the greater the equivalent thermal conductivity, a thickness of the liquid earlier into the two-phase region, corresponding , The greater the thickness of the two-phase zone, the smaller the temperature gradient in the two-phase zone and the longer the local solidification time. By using the calculated quadratic dendrite spacing and the measured value, the equivalent factor (m) can be obtained Reasonable value; for the casting machine, forced convection area in the liquid phase m = 7, forced convection and natural convection transition zone m = 5, the natural convection zone m = 3, static zone m = 1 calculation , You can get more accurate simulation results.