旋转电极电渣重熔过程电极熔速的理论解析

摘要：旋转电极电渣重熔通过改变结晶器内熔体的流动和传热规律，增强了渣池与电极间的对流换热，在提高电极熔化速率和生产效率方面具有巨大潜力。提出了电渣重熔过程电极熔化速率的求解方法，并考虑了电极旋转时的强制对流，基于多物理场耦合模型预测了电极直径、转速对电极熔化速率的影响规律。结果表明，随着转速提高，金属液滴由从电极中心滴落向电极边缘滴落转变，高温区由渣池外侧向渣池中心移动。当转速从0增大至90r/min，55mm直径电极的熔化速率从7.90g/s增大至9.68g/s，对比固定电极，转速为90r/min时，生产效率最多提高了22.5%；进一步增大转速，电极熔化速率反而减小。存在一个最佳转速可使熔化速率达到最大，且该最佳转速随着电极直径的增大而减小。

Theoretical analysis of electrode melting rate during electroslag remelting with a rotating electrode

Electroslag remelting (ESR) with a rotating electrode can enhance the convection heat transfer between slag pool and electrode by changing the flow and heat transfer laws of melts in the mold. ESR with a rotating electrode was supposed to have great potential in improving the melting rate and production efficiency. A method for calculating the electrode melting rate in ESR process was proposed. The forced convection during the rotation of electrode was considered. The influences of electrode diameter and rotation speed on the electrode melting rate were predicted based on a multi physical field coupling model. The results show that with the increase of rotating speed, the dropping position of metal droplets under the electrode tip changes from the center to the edge, and the high temperature region in the slag pool moves from the outside to the center. As the rotating speed increases from 0 to 90r/min, the melting rate of the 55mm diameter electrode increases from 790g/s to 968g/s. Compared with the ESR with a fixed electrode, the production efficiency is improved by up to 225% when the rotating speed is 90r/min. However, the melting rate decreases with a further increase of rotating speed. There is an optimum speed to achieve a maximum melting rate, which decreases with the increase of electrode diameter.