M-EMS对45钢矩形坯铸态组织和溶质分布均匀性的影响  

Effect of M-EMS on the as-cast structure and solute distribution homogeneity of 45 steel rectangular blooms

作　　者：陈亮[1] 汤群伟 王璞 陈刚 扈凯 李伟涛 张家泉[1] CHEN Liang;TTANG Qunwei;WANG Pu;CHEN Gang;HU Kai;LI Weitao;ZHANG Jiaquan(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Technology Center,Weifang Iron&Steel Group Co.,Ltd.,Weifang 262400,Shandong,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]潍坊特钢集团有限公司技术中心,山东潍坊262400

出　　处：《连铸》2024年第2期45-49,共5页Continuous Casting

基　　金：国家自然科学基金资助项目(U1860111)。

摘　　要：以某钢厂断面尺寸200 mm×240 mm的45钢连铸矩形坯生产为例,通过工业试验探究了M-EMS电流强度对铸坯铸态组织和溶质分布均匀性的影响。结果表明,M-EMS会使铸坯柱状晶产生一定角度的偏转,中心的等轴晶率随M-EMS电流强度增大而增大;然而,相较于等轴晶区,柱状晶区的溶质分布均匀性更好;在较大的M-EMS电流强度下,由于钢液的冲刷作用,铸坯皮下产生了负偏析,其位置与枝晶偏转区域相对应,同时在铸坯内部CET位置处产生了较严重的正偏析,铸坯均质性恶化。适当降低M-EMS电流强度,尽管铸坯等轴晶区面积减小,但其全断面的成分均匀性得到明显提高,其中,等轴晶区的碳极差和标准差均比强搅拌工况下降低一半以上,有效提升了铸坯全断面的均质性。The production of 45 steel continuous casting rectangular bloom with a cross-section of 200 mmX 240 mm in a steel plant is taken as an example,and the effects of M-EMS current intensity on the microstructure and solute distribution uniformity of the billet were investigated by industrial experiments.The results show that M-EMS can produce a certain angle deflection of columnar crystals in the bloom castings,and the equiaxed grain ratio increases with the enhancing M-EMS current intensity.It is noted,however,that the solute distribution uniformity in the columnar crystal region is much better as compared to in the equiaxed crystal region.Additionally,a under skin negative segregation band occurs frequently while with the conventional high M-EMS current intensity,which,corresponding to the dendritic deflection area as well,should be produced by the EMS induced liquid flow scouring effect of molten steel.At the same time,severe positive segregation is often observed at the CET position inside the strand,which deteriorates the homogeneity of the strand remarkably.By appropriately reducing the M-EMS current intensity,the composition uniformity of the bloom entire cross-section is significantly improved,although the equiaxed crystal area of the strand decreases.Accordingly,the carbon extreme range and standard deviation of the equiaxed crystal zone are reduced by more than half compared to those under strong stirring conditions,which is beneficial to an upgrading chemical homogeneity of the bloom castings.

关 键 词：矩形坯 M-EMS 铸态组织 均质性 枝晶偏转 柱状晶向等轴晶转变 

分 类 号：TF777[冶金工程—钢铁冶金]