方坯凝固过程中夹杂物的运动轨迹

Trajectories of Inclusions During Solidification of Steel Square Billet

考虑糊状区多孔介质对流动的影响 ,建立了三维凝固耦合模型和夹杂物运动轨迹方程 ,并与CFX F3D软件包相结合 ,对方坯凝固过程中夹杂物颗粒的运动轨迹进行了数值模拟·结果表明 :夹杂物颗粒在结晶器凝固过程中的运动轨迹与夹杂物在水口处的初始位置、夹杂物直径和结晶器内的流场特性有关 ;微观夹杂物易滞留于铸坯中 ,不易排除 ,直径较大的大颗粒夹杂物易于上浮排除 ;凝固对夹杂物的运动轨迹有显著影响 ,有利于夹杂物上浮去除 ;流场是影响夹杂物运动轨迹的主要因素·

Considering the influence of porous media in mush, a three dimension coupled solidification mathematical model and the trajectories equation of inclusions was developed and the model was used with CFX F3D commercial software to study the trajectories of inclusions in solidification of square billet. The numerical results show that the initial position at inlet of nozzle and diameter of inclusions, the characteristics of flow field have effect on the trajectory and the distribution of inclusions in the billet. The microscopic inclusions in billet is difficult to be removed from the billet; whereas the large size inclusions have small amount residuals in the billet. The solidification influences the trajectories of inclusions and tend to remove them and the fluid field characteristic is the major factor which influence the trajectories of inclusions.