中文摘要：

采用Procast软件中的Mile算法对Ag-28Cu合金连铸凝固过程中温度场的非稳态变化进行了模拟,研究了不同拉速、过热度和换热系数对温度场分布、凝固速率和凝固前沿温度梯度变化的影响。模拟结果表明：随拉速的增大,铸件中心区域的凝固速率加快,凝固前沿温度梯度变化范围减小。换热系数的改变在靠近铸件表面区域对凝固速率基本没有影响,但靠近铸件中心区域后,其凝固速率随换热系数开始大幅度增大。在整个凝固过程中,换热系数越大,凝固前沿温度梯度越大。随浇注温度的提高,其凝固速率呈振荡式增大,凝固前沿温度梯度呈振荡式减小。

英文摘要：

The Mile（Mixed Lagrangian Eulerian） algorithm of procast software was used to simulate the process of unsteady temperature field for Ag-28 Cu alloy in continuous casting. The change of the temperature field distribution, solidification rate and the temperature gradient of the solidification front was studied on different pulling speed, degree of superheat and heat transfer coefficient. Simulation results show that the larger the drawing speed is, the faster the solidification rate of the central region is, the smaller the temperature gradient is. A change in heat transfer coefficient has no effect on solidification rate in the area near casting surface. But in the area near the center of the casting, the solidification rate starts to increase substantially along with the increase of heat transfer coefficient. During the solidification process, the larger the heat transfer coefficient is, the greater the temperature gradient is. With the rise of pouring temperature, a vibrating increase of the solidification rates occurs while the temperature gradient of solidification front decreases in the way of vibrating.