脉冲电流作用下金属熔体内电磁场分布的数值模拟

 将脉冲电流作用于铁素体不锈钢，发现经过脉冲电流处理后等轴晶比例大幅增加，晶粒明显缩小。建立了考虑集肤效应的三维电磁场瞬态有限元模型，利用ANSYS软件对电极及熔体内的电场、磁场、电磁力分布进行了计算，结果表明，由于集肤效应使得电磁场主要集中在电极周围和熔体上部，且在脉宽的后期电磁场的方向由于涡流的存在而发生变化；电极间距对熔体电磁场均匀性具有较大影响；随着脉冲电流的脉宽减小，熔体上部的电磁场增强，但集肤深度也越小，同时作用时间缩短。

Numerical Simulation of the Electromagnetic Field in Molten Metal Under Electric Current Pulse

The effect of electric current pulse on the solidified microstructure of ferrite stainless steel was investigated.The results show that microstructure is considerably refined to equiaxed grains,and the average grain size is also decreased dramatically.3D finite element model was developed to simulate the electromagnetic filed in the molten metal,especially considering the skin effect.The distribution of electric field,magnetic filed and electromagnetic force was calculated using ANSYS software.The results show that electromagnetic field is mainly distributed around the electrodes and on the top of the melt,and the direction of electromagnetic field is greatly changed in the later period of pulse width because of the eddy current.The distance between electrodes has more influence on the uniformity of electromagnetic field.With the decrease of pulse width,the skin effect become more seriously,but the duration time is shortened.