励磁电流对结晶器内磁场和电磁力的影响

Effects of Exciting Current Density on Distribution of Magnetic Field and Electromagnetic Force in Mold

利用建立的软接触电磁连铸结晶器内三维电磁场计算数学物理模型,模拟分析了高频磁场励磁电流密度在2.2×106～1.32×107A/m2之间变化时,对结晶器内磁感应强度和钢液内电磁压力的影响。结果表明,提高励磁电流密度,可以有效地提高结晶器内初始凝固区域的磁感应强度和电磁压力,但同样会使钢液或铸坯表层的磁感应强度和电磁压力在同一高度的周向上分布的不均匀性增加,切缝附近明显高于分瓣体中心;同时励磁电流密度增加,电磁压力沿结晶器高度方向的变化梯度随之大幅度增加,均匀性下降。为保证铸坯质量,应控制励磁电流密度在合适范围内。

Based on the established mathematical and physical model for calculating the three-dimensional electromagnetic field in soft-contact continuous casting mold,effects of exciting current density,varied at 2.2×106 A/m2 to 1.32×107 A/m2,on the distribution of magnetic induction intensity and electromagnetic forces in soft-contact mold were simulated. The results show that the magnetic induction intensity and electromagnetic force in the surface layer of molten steel or billet can be effectively increased in the beginning solidification region ,however,the heterogeneities of magnetic induction intensity and electromagnetic forces along the circumference direction are enhanced with the increase of exciting current intensity. The values of magnetic induction intensity and electromagnetic forces at slits are evidently higher than that at the segment center. Besides,change gradient of electromagnetic forces along height direction of mold is increased with increasing in exciting current density,resulting in the deterioration of homogeneity. So the exciting current density should be controlled at a accepted range to ensure the quality of billet.