连铸中间包结构优化及夹杂物去除的水模拟研究

A Study on Water Simulation for Optimizing Tundish Structure and Inclusion Removal in Concasting

以25t中间包为原型,通过实验相似比λ=1:2.3的水模型,分析了4流近似T型中间包3种挡墙形式包内流场及夹杂物去除。结果表明,原挡墙控流下的中间包同一侧两流之间的流体流动特性差异很大,与内侧相比,外侧流的最短停留时间和峰值时间长、死区体积大,造成中间包内钢液温度不均匀,夹杂物不能有效地上浮去除;U-型挡墙能延长峰值时间,但是最短停留时间短,死区比例较大;采用Y-型挡墙可以有效地改变中间包内流场分布,促进夹杂物上浮。30CrMo钢工业试验表明,采用Y-型挡墙钢中大型夹杂物较原用挡墙降低16.9%。

According to prototype 25 t tundish, the liquid flow field and the removal of inclusions in an approximate T-shape tundish with three kinds of weirs in 4-strand casting have been analyzed by using experimental similarity ratio A = 1： 2.3 water model. Resuhs showed that by using original weir, there was a great difference in flow characteristics between two outlets at the same side of tundish, and compared to inside outlet the outside outlet had longer minimum residence time and peak time and large dead zone volume led to liquid temperature variation and delaying inclusion floatation; by using U-type weir, the peak time eouhl be prolonged, but with short minimum residence time and large dead zone volume; and by using Y-shape weir it was available to efficiently change the liquid flow distribution in tundish and improve inclusion removal. The commerial test for steel 30CrMo indicated that with using Y-weir the large inclusion anlount in steel decreased by 16.9% as compared with using original weir.