高拉速薄板坯结晶器内流场行为分析

Study on flow field behavior in thin slab mold with high casting speed

针对某钢厂薄板坯结晶器内易发生卷渣问题,采用漏斗形结晶器为研究对象,通过VOF的方法建模计算,对钢-渣界面进行深入研究,并构建1∶2的物理模型与1∶1的数值模型,分析拉速、保护渣黏度以及浸入深度对结晶器流场和钢-渣界面波动行为的影响。以表面流速大小、钢-渣界面渣相分布和结晶器液面波动高度等作为评判依据。结果表明:在钢-渣界面表面流速为0.12~0.26 m/s,且保护渣黏度大于0.253 Pa·s时,液面比较平稳。随着浸入深度增加,钢液的冲击深度下移,上回旋区范围变大,钢-渣界面波动高度降低到5.4 mm。当浸入深度大于190 mm,保护渣黏度为0.324 Pa·s,钢-渣界面表面流速小于0.26 m/s时,可以有效抑制卷渣的发生,这对于提升铸坯质量,助力工业生产安全稳定提供参考。

Aiming at the problem of the slag entrapment in the thin slab mold of a steel mill,the funnel mold was used as the research object,and the VOF method was established to model and calculate the steel-slag interface,and the 1:2 physical model and 1:1 numerical model were constructed to analyze the effects of casting speed,viscosity of mold flux and immersion depth on the flow field of the mold and the fluctuation behavior of the steel-slag interface.The surface velocity,the phase distribution at the steel slag interface,and the height of the liquid level fluctuation of the mold were chosen as the evaluation standard.The results show that the liquid level is relatively stable when the flow rate of steel-slag interface is 0.12-0.26 m/s and the viscosity of the slag is greater than 0.253 Pa·s.With the increase in immersion depth,the impact depth of the molten steel decreases,the range of the upper turning zone becomes larger,and the fluctuation height of the slag interface decreases to 5.4 mm.When the immersion depth is greater than 190 mm,the viscosity of the mold flux is 0.324 Pa·s,and the surface flow rate of the steel slag is less than 0.26 m/s,the appearance of slag rolling can be effectively inhibited,which provides a reference for improving the quality of the casting billet and the safety and stability of industrial production.