模底砖结构对大钢锭充型过程卷渣的影响

通过建立19 t大钢锭充型过程的流动和传热模型，研究大钢锭充型初期的流场和温度场分布特征，针对一系列不同尺寸结构模底砖的钢锭模进行充型过程的数值模拟，研究模底砖结构对充型初期钢液面卷渣的影响。充型初期钢液面波动大，且凝固层推进快，易发生卷渣并被捕获至坯壳。当模底砖下口直径小于上口直径时，钢液进入钢锭模的流速主要取决于模底砖下口直径，并随着下口直径的增大而迅速减小。对于19 t钢锭，当模底砖下口直径大于90 mm后能在很大程度上减小充型初期的卷渣概率。

Influence of entrance nozzle structure on mould powder entrapment during filling process of large steel ingot mould

A model for fluid and heat transfer of early stage of filling of a 19 ton ingot mould was built, and the flow and tempera-ture distribution characteristics during early stage of filling were investigated. Numerical simulations of mould filling with a series of en-trance nozzles with the different top diameters and bottom diameters were carried out, and the effects of entrance nozzle structure on mould powder entrapment during early stage of filling were investigated. The results show that level fluctuation in molten steel is strong and solidified shell grows fast so that mould powder can be entrapped easily. When top-end interior diameter is larger than bottom-end, the velocity of molten steel stream depends on the bottom-end interior diameter, and decreases with the increasing of op-end interior di-ameter. As for 19 ton steel ingot, the risk of mould powder entrapment can be greatly decreased when the bottom-end interior diameter is larger than 90 mm.