材料期刊网

基于Ｍａｘｗｅｌｌ方程组及有关的电磁场理论，提出了更切合实际情况的电渣重熔体系内磁场的数学模型，并应用于结晶器直径２００ｍｍ的实验室重熔装置．对直径７６ｍｍ低碳低合金钢电极的重熔过程（３０００Ａ（有效值），ＣａＦ２＋３０ｍａｓｓ％Ａｌ２Ｏ３＋２０ｍａｓｓ％ＣａＯ渣系），结果表明，磁场强度的幅模在电极内沿端部锥体形成方向不断增大，至接近锥顶处达最大值，约为２．６×１０４Ａ／ｍ，此后在渣池、锭子熔池、液固两相区和固态锭子内沿轴向向下逐渐减小；沿半径方向，在电极和渣池内呈现一峰值，在液、固金属区内则单调增大至边界条件限定值．对在直径１４０ｍｍ的结晶器中以直径８０ｍｍ的电极和ＣａＦ２＋ＣａＯ＋Ａｌ２Ｏ３＋ＭｇＯ渣系生产高速钢（Ｍ２）锭的过程，以该模型估计的重熔体系渣池和金属熔池内磁场强度（幅模）的大小和分布与实测结果较相吻合．该模型可作为研究电渣重熔体系内熔体流动，传热和传质过程的基础．

A mathematical simulation and its application to laboratory 200 mm diameter mould of ESR unit were developed based on Maxwell's equations and related electromagnetic field theorem. For remelting a low carbon alloy steel(an electrode of 76 mm in diameter, 3000 A current (rms) and the slag of CaF2+30 mass-% Al2O3+20 mass-% CaO system) with the parameturs selected reasonably,the amplitude magnetude of magnetic field intensity inner the electrode along the formation direction of electrode tip cone is continuously increasing to a maximum value being about 2.6×104 A/ m near the cone top, then decreasing in the slag bath, ingot pool, mushy zone and solid ingot. For a high speed steel(M2) ingot on another unit with a mould of 140 mm in diameter (80 mm diameter electrode and the slag of CaF2+CaO+Al2O3+MgO system), the predicted magnitude and profile of the magnetic field intensity in the slag bath and ingot pool of the system by the model are in pretty good agreement with the practical measurements. This model may be used as a good and reliable basis for the further study on the fluid flow and the heat and mass transfer processes in ESR system .Correspondent: WEI Jihe, professor,(Department of Materials Science and Engineering, Shanghai University,Shanghai 200072)