基于有限差分法的单晶热型连铸凝固过程的数值模拟

Numerical Simulation of Solidification in OCC Process Based on the Finite Difference Method

采用有限差分法对金属单晶热型连铸凝固过程的温度场进行数值模拟,对不同工艺组合下的液固界面曲线进行分析和比较,确定了连铸速度、冷却水流量、冷却距离、铸型温度等主要工艺参数对液固界面位置和形状的影响,其中连铸速度对凝固界面形状的影响不大,但对其位置的影响较大;改变冷却水流量和冷却距离均可调节冷却强度,相比之下,冷却距离对液固界面的影响更大;铸型温度对固液界面位置的影响较大,应进行准确控制。实际操作中可采用较小的冷却距离,同时适当提高连铸速度,保持铸型温度略高于金属熔点。

The temperature field of the solidification process of hot mould continuous casting was simulated by finite difference method and the profiles of solid-liquid interface under different parameters were plotted and analyzed. It is found that the casting rate, the hot mold temperature and the cooling condition have influenced on the location and profile of the solid-liquid interface. The casting rate affects greatly on the location but little on the shape of the interface. Comparably, the cooling distance has much effect than cooling water flow on both aspects. In order to accurately controll the solid-liquid interface and to obtain high quality single crystal, it is better to maintain relative small cooling distance. Meanwhile the casting rate can be speed up. And the mold temperature should be hold above the metal melting point.