凝固传热模型在静态轻压下技术中的应用

在实测铸坯表面温度的基础上,通过对各冷却段界面换热系数进行修正,建立了适合实际工况条件的凝固传热数学模型,并将模型计算结果应用于静态轻压下试验中,取得了良好的效果。研究结果表明:实施轻压下最佳的工艺条件为:过热度10～30℃、二冷比水量0.28 L/kg、拉速0.85 m/min,压下量8 mm;采用轻压下技术后,铸坯的中心疏松级别由原来的2.0～2.5级降低为1.0～1.5级;V型偏析和中心缩孔有所改善;铸坯的中心平均碳偏析指数由1.17～1.26降低为1.07～1.13。

Application of Solidification Model to Static Soft Reduction

Based on the measurement of surface temperature on the bloom, mathematical model for solidification heat transfer is presented according to modifying the heat transfer coefficient of different cooling zone and the calculating results of the model are applied to the static soft reduction well. The results show that the best casting condition for soft reduction is liquid steel overheat 10-30℃, secondary intensity 0. 28 L/kg, casting speed 0.85 m/min and reduc-tion amount 8 mm. Using soft reduction technology can decrease the grade of center porosity from 2.0-2.5 to 1.0-1.5, the V-shape segregation and center shrinkage cavity are improved, and the center average carbon segregation index of the bloom decreased from 1.17-1.26 to 1.07-1.13.