三相非平衡线性电磁搅拌改善铸坯凝固组织的分析

Solidification Structure of Casting Billet Improvement Through Linear Electromagnetic Stirring with Three Unbalanced Currents

采用三相通入不同电流的非平衡线性电磁搅拌技术进行了铸坯的静态浇铸实验 ,并对电磁搅拌过程中钢液内的电磁力各分量的瞬时值进行了理论分析·结果表明 ,当采用将电磁搅拌器的三相通入不同电流的非平衡线性电磁搅拌时 ,在钢液内所产生的电磁力是脉动的 ,其大小呈周期性变化 ,尤其是垂直于磁场运动方向上的电磁力 ,其脉动的幅度很大·由此认为 ,当采用将搅拌器的三相通入不同电流的非平衡线性电磁搅拌时 ,所产生的垂直于磁场运动方向上的脉动电磁力是提高等轴晶比率 。

Casting experiments were carried out through linear electromagnetic stirring with three unbalanced currents, then the electromagnetic forces in the molten steel were theoretically analyzed. The results show that the equiaxed zone ratio of the casting billet is greatly increased,with its soidification structure is obviously improved,and the momentum values of the electromagnetic forces both parallel to and perpendicular to the direction of the traveling magnetic field pulsate periodically with time. Furthermore the electromagnetic forces perpendicular to the direction of the traveling magnetic field, which is also perpendicular to the direction of the molten steel flow,pulsate much greatly. The pulsatile forces are believed one of the most important factors in improving the solidification structure of the casting billet.