大圆坯连铸宏观偏析形成过程的数值模拟  

Numerical simulation of macrosegregation formation in large round bloom continuous casting

作　　者：李曜光 陈卫强[1] 曹学欠[1] 樊伟亮 LI Yaoguang;CHEN Weiqiang;CAO Xueqian;FAN Weiliang(Steelmaking Engineering Technology Institute,Capital Engineering and Research Incorporation Limited,Beijing 100176,China)

机构地区：[1]中冶京诚工程技术有限公司炼钢工程技术所,北京100176

出　　处：《炼钢》2024年第3期56-65,共10页Steelmaking

摘　　要：针对Φ785 mm立式连铸大圆坯,建立了流动、传热、凝固、传质三维耦合模型。通过该模型预测了从弯月面到完全凝固范围内铸坯溶质元素的分布情况,研究了大圆坯宏观偏析形成过程。模拟结果表明:连铸前期钢液对凝固前沿的溶质冲刷效应是铸坯表面区域出现明显负偏析带的主要原因;随着钢液的不断凝固,铸坯中心区域残余液相的溶质元素不断富集,最终导致了中心偏析的产生,C元素中心最大正偏析指数为1.08;另外,不同溶质元素宏观偏析严重程度有所不同,但呈现出的分布趋势基本相同。The three-dimensional coupled model was developed to consider the turbulent flow,heat transfer,solidification,and solute transport phenomena during the vertical continuous casting forΦ785 mm large round bloom.By using the model,the distribution of solute elements in the bloom from meniscus to full solidification was predicted,and the formation process of macrosegregation in the large round bloom continuous casting was examined in detail.The simulation results show that the“solute washing effect”of molten steel on the solidification front at the early stage of continuous casting is the main reason for obvious negative segregation band in round surface region.With the continuous solidification of molten steel,the solute elements of residual melt in the round center are continuously enriched,resulting in the formation of center segregation.The central maximum positive segregation index of C is 1.08.In addition,the severity of macrosegregation for different solute elements is different,however the distribution for different elements exhibits the same tendency.

关 键 词：大圆坯 流场 凝固 宏观偏析 数值模拟 

分 类 号：TF777.5[冶金工程—钢铁冶金]