基于一维稳态传热的纯金属热型连铸模型化分析

Modeling Analysis of Pure Metal Continuous Casting with Heated Mould Based on One-dimensional Steady-state Heat-transfer

基于已有的热型连铸一维稳态传热模型及其分析解,导出了固-液界面前沿液相的温度梯度GL和冷却速度RL随拉铸速度V变化的关系式。计算结果表明,稳态热型连铸过程中,铸坯固-液界面前沿液相温度梯度GL随着拉铸速度V的增加而减小;固-液界面前沿液相的冷却速度RL随拉铸速度V呈非单调变化,存在一个最大值。在"铸型温度-拉铸速度"坐标系中绘制出固-液界面位置h、温度梯度GL和冷却速度RL的等值线图,全面反映了稳态热型连铸过程中工艺参数的变化规律。计算所得的工艺相图与文献中由实验结果总结出的工艺相图相符。

Based on the one-dimensional steady-state heat-transfer model which had been suggested on heated mould continuous casting of pure metals,the relationship of the temperature gradient GL of liquid phase in front of solid-liquid interface to casting speed V and that of the cooling rate RL have been deduced.It is indicated by calculations that, during a heated-mould continuous casting process, the temperature gradient GL reduces with increasing of casting speed V when the position of solid-liquid interface is constant. But the cooling rate of liquid phase in front of solid-liquid interface rises first and lowers later. There is a maximum value of the cooling rate RL with increasing of casting speed. The＇ isolines of temperature gradient GL, cooling rate RL and solid-liquid interface position h,which are drawn in the coordinate map of mould temperature and casting speed, present the variation rules of technique parameters during a steady heated-mould continuous casting process. A perfect regime diagram can be obtained, which has been verified by the experimental results in literatures.