大断面宽厚板坯结晶器流场数值模拟研究

Numerical Simulation Study on Flow Field of Mold for Large-section Slab

结晶器内钢液流场对铸坯质量至关重要,特别是对大断面宽厚板坯,严重时会使铸坯表面产生纵裂纹或铸坯内部产生夹杂缺陷。本文采用数值模拟的方法,利用ANSYS及Tecplot等软件,对湘钢宽厚板厂常用260 mm×2070 mm断面结晶器流场进行研究,并单独进行了网格无关性验证。分析拉速及水口浸入深度的改变对结晶器内流场的影响,发现拉速或浸入式水口深度改变时,流场整体形态无明显变化,但上下流股涡心位置及钢液对窄面冲击点位置有所改变。验证了现场所执行工艺参数的可靠性,制定了拉速调整及水口浸入深度调整的操作规程,对现场生产做出了指导。

The flow field of molten steel in the mold is very important to the quality of the casting slab,especially for the wide and thick slab with large section.Longitudinal cracks on the surface of the casting slab or inclusions in the slab will occur in serious cases.In this paper,the numerical simulation method and the software of ANSYS and Tecplot are used to study the flow field of mold with 260 mm×2070 mm section commonly used in Heavy Plate Plant of XISC,and grid-independent verification is carried out separately.The influence of different casting speed and nozzle immersion depth on the flow field of the mold was analyzed.It was found that when the casting speed or immersion nozzle changed,the overall flow field morphology did not change significantly,but the position of eddy centers in the upstream and downstream strands and the position of impact points on the narrow surface changed.The reliability of the process parameters was verified,and the operating procedures for the adjustment of the casting speed and the immersion depth of the water nozzle were formulated,which provided guidance for the on-site production.