小方坯连铸机结晶器工艺参数对卷渣的影响

Influence of small billet casting mold process parameters on slag entrapment

以165 mm×165 mm连铸小方坯结晶器为研究对象,通过大涡模拟模型,研究不同拉速、不同水口深度对结晶器内流场、液面波动、卷渣的影响,给出控制方程和边界条件;模拟研究电磁搅拌前后的流场速度分布及卷渣现象;确定了电磁搅拌前后的卷渣速率,拉速对渣相分布的影响及拉速对液位波动的影响。通过采取严格控制拉速至1.3 m/min,增大水口浸入深度至120~130 mm,选用性能合适的保护渣并适当提高其黏度等优化工艺措施,优化后10 kg铸坯夹杂物的平均质量由11.6 mg降至6.4 mg,夹杂物平均尺寸由4.41μm降至1.13μm,连铸坯内部质量得到显著改善。

Taking 165 mm×165 mm continuous casting billet mold as research object,large eddy simulation model is used to study effects of different casting speeds and nozzle depths on flow field,liquid level fluctuations,and slag entrapment inside mold.The control equation and boundary conditions are given.The velocity distribution of flow field and slag entrapment phenomenon before and after electromagnetic stirring were simulated;Determined slag entrapment rate before and after electromagnetic stirring,the influence of casting speed on slag phase distribution,and the influence of casting speed on liquid level fluctuation.By strictly controlling casting speed to 1.3 m/min,increasing nozzle immersion depth to 120~130 mm,selecting suitable protective slag and increasing its viscosity,and other optimization process measures,after optimization average mass of 10 kg billet inclusions decreased from 11.6 mg to 6.4 mg,and average size of inclusions decreased from 4.41μm decreases to 1.13μm.Internal quality of continuous casting billets is significant improvement.