二冷电磁搅拌对无取向硅钢连铸坯质量的影响

Effect of electromagnetic stirring in secondary cooling zone on quality of continuous casting slab of non-oriented silicon steel

研究了二冷电磁搅拌参数对无取向硅钢XG800 WR连铸板坯等轴晶率、中心偏析及白亮带的影响。结果表明,搅拌电流从0A增加到400 A,铸坯等轴晶率由19.6%增至26.5%;搅拌频率从0Hz增加到8 Hz,等轴晶率由21.7%增至26.1%。随搅拌电流增加,铸坯中心S、Si、Mn的偏析度先减小而后增加;搅拌强度过大,铸坯出现白亮带,白亮带处Si、Mn、S产生负偏析,S的负偏析最大,相应会导致铸坯中心S、Si、Mn元素的正偏析显著增加。综合考虑增加铸坯等轴晶率和减轻中心偏析以及避免产生白亮带,选取350 A/6 Hz的电磁搅拌参数为最佳。

The effect of electromagnetic stirring parameters in secondary cooling zone on equiaxial crystal rate, center segregation and white band of continuous casting slab of XG800WR non-oriented silicon steel was investigated. The results show that the equiaxial crystal rate of slab grows from 19. 6 % to 26. 5 % when stirring current varies from 0 A to 400 A. The equiaxial crystal rate of slab grows from 21.7 % to 26. 1% when stirring frequency increases from 0 Hz to 8 Hz. With stirring current increasing, the segregation degree of S, Si, Mn in slab center is firstly decreased and then increased. When stirring intensity is excessive the white band appears and in the area of the white band the negative segregation of Si, Mn and S occurs and the negative segregation index of S is the largest. All of the phenomena will consequently lead to an increase of positive segregation of S, Si and Mn in the center of slab. In a comprehensive consideration of increase of the equiaxial crystal rate, reduction of central segregation and avoidance of white band occurrence the 350 A/6 Hz is selected as the optimal electromagnetic stirring parameters.