高拉速薄板坯连铸结晶器钢渣界面波动分析

Analysis on interface fluctuation of steel slag in mold of high casting speed thin slab continuous casting

为应对提高拉速薄板坯结晶器内钢液不稳定行为,以1 520mm×90mm薄板坯结晶器为研究对象,利用液面追踪技术VOF方法建模计算,对薄板坯钢渣界面进行了深入研究,实现了对薄板坯连铸结晶器内流体流动及钢/渣界面行为的模拟计算。并结合实际生产工艺,采用1∶1物理模型和数值模拟相互验证,分析了拉坯速度、浸入深度和保护渣黏度种类对结晶器流场及钢渣界面的影响。结果表明,当结晶器钢液面流速为0.20~0.25m/s,且界面较平稳时,保护渣黏度高于0.237Pa·s可以适用;当钢液流速为0.25~0.30 m/s,保护渣黏度为0.382Pa·s时,现场低碳钢卷渣率小于0.5%,表现出良好的抗卷渣能力。

In order to deal with the instability behavior of molten steel in the thin slab mold with increasing casting speed,taking the 1 520 mm×90 mm thin slab mold as the research object,the liquid level tracking technology VOF method was used to model and calculate the steel slag interface in the thin slab continuous casting mold.The fluid flow and the behavior of steel/slag interface in thin slab continuous casting mould were simulated.Combined with the actual production process,the effects of casting speed,immersion depth and mold flux viscosity on mold flow field and slag interface were analyzed by 1∶1 physical model and numerical simulation.The results show that when the liquid steel flow rate is 0.20-0.25 m/s and the interface is stable,the mold flux viscosity higher than 0.237 Pa·s can be applied.When the liquid steel flow rate is 0.25-0.30 m/s and the viscosity of mold flux is 0.382 Pa·s,the slag entrapment rate of low carbon steel is less than 0.5%,showing good slag entrapment ability.