电渣重熔过程中传热及凝固组织的数值模拟

在凝固传热数学模型基础上,采用正态分布形核模型和二维偏心生长模型,模拟了钢锭重新凝固过程温度场及钢锭凝固组织的生长情况.数值结果表明：电渣重熔钢锭以倒“V”形的柱状晶为主,中心和底部为等轴晶,模拟结果与实验结果符合良好.随着渣温的提高,熔池变得深且宽;随着侧壁换热系数的增大,熔池深度变浅;随着重熔速度的减小,熔池深度也逐渐变浅;较低的渣池温度、较大的对流换热系数有利于等轴晶形成,而重熔速度对凝固组织的影响不大.

The Numerical Simulation of Heat Transfer and Solidification Structure in ESR System

In order to investigate ESR process, solidification and heat-transfer model, normal distribution nucleation model and two-di- mensional eccentric square model were solved to study the temperature field, and the growth of ingot microstructure during ingot re-soli- dification. Numerical results showed that ESR ingot has a invert V-shaped columnar grain zone and equiax grain zone at the center and the bottom, and the predicted solidification structure agrees well with the experimental result. The melting pool becomes deeper and wider with the increase of the temperature of slag pool; the depth of melting pool becomes shallower with the increase of the coefficient of heat transfer and the decrease of the remelting rate; low temperature of slag pool and large coefficient of heat transfer are two key factors to promote the formation of equiax grain, but remelting rate have a little effect on the solidification structure.