工程科学学报，第41卷，第6期：748-756,2019年6月 Chinese Journal of Engineering,Vol.41,No.6:748-756,June 2019 DOI:10.13374/j.issn2095-9389.2019.06.006:http://journals.ustb.edu.cn 圆坯凝固末端电磁搅拌作用下的流动与传热行为 李少翔”，王璞”，兰鹏”，刘华松”，刘麒麟》，李树贵》，张家泉)回 1)北京科技大学治金与生态工程学院，北京1000832)宝山钢铁股份有限公司，上海201900 ☒通信作者，E-mail:jqzhange@metall.ustb.cdu.cn 摘要以特殊钢圆坯连铸为研究对象，建立了研究凝固末端电磁搅拌作用效果的三维耦合数值模型.利用分段计算模型获 得末端电磁搅拌区域钢液流动与凝固的实际状态，并采用达西源项法处理凝固末端钢液在糊状区的流动，研究了不同电磁搅 拌工艺参数下的电磁场分布及钢液的流动与传热特征.通过测量搅拌器中心线磁感应强度和铸坯表面温度验证了模型的准 确性.研究结果表明：电流强度每增加100A,搅拌器中心磁感应强度增加19.05mT,电磁力随着电流强度的增加显著增大. 在20~40Hz范围，随着电流频率的提高，中心磁感应强度略微下降，但电磁力仍有所增加.在搅拌器区域，液相穴内的钢液在 切向电磁力的作用下旋转流动，其切向速度随着电流强度和频率的增加而变大·末端电磁搅拌可促进钢液在圆坯径向的换 热，随着电流强度和频率的提高，铸坯中心轴线上的钢液温度降低，同时末端搅拌位置处的中心固相分率增加. 关键词圆坯连铸：凝固末端电磁搅拌：电磁场：糊状区流动：传热 分类号T777.4 Melt flow and heat transfer at the crater end of round billet continuous casting using final electromagnetic stirring LI Shao--xiang”,WANG Pu”,LAN Peng',LIU Hua-song',LIU Qi-lin》,lShu-gi,ZHANG Jia-uan》g 1)School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Baoshan Iron Steel Co.,Ltd.Shanghai 201900,China Corresponding author,E-mail:jqzhang@metall.ustb.edu.cn ABSTRACT Final electromagnetic stirring (F-EMS)is widely used in the billet and bloom continuous casting process because it ef- fectively improves the as-east quality.Numerous industrial trials on F-EMS have been conducted:however,the real melt flow and heat transfer characteristics at the crater end remain unclear.In this study,based on a round billet special steel continuous casting process, a coupled three-dimensional numerical model was developed to describe the F-EMS phenomenon.The flow and solidification behavior of the melt in the F-EMS region were obtained by a segmentation calculation model,and the Darcy source term method was employed to suppress the velocity within the mushy region.The effect of stirring current intensity and frequency on the electromagnetic field,melt flow,and heat transfer was investigated numerically.The model was validated using the measured data of magnetic flux density in the stirrer center and the strand surface temperature.According to the simulation results,with every 100 A increase in the current intensi- ty,the maximal magnetic flux density increases by 19.05mT.The electromagnetic force significantly increases with the increase in cur- rent intensity.With the increase in current frequency within 20-40 Hz,the magnetic flux density decreases slightly,whereas the elec- tromagnetic force increases.Moreover,a swirling flow field in the stirrer region is observed under the rotary electromagnetic force,and the tangential velocity of melt increases with the increase in current intensity and frequency.Additionally,the swirling flow enhances the local melt heat transfer at the radial direction of the round strand.As the current intensity and frequency increase,the temperature of the melt in the liquid core decreases,and the center solid fraction at the F-EMS-implemented position increases accordingly. 收稿日期：2018-11-30 基金项目：国家自然科学基金资助项目(U1860111):北京科技大学本科教有教学改革项目(JG2017M11)工程科学学报，第 41 卷，第 6 期: 748--756，2019 年 6 月 Chinese Journal of Engineering，Vol． 41，No． 6: 748--756，June 2019 DOI: 10． 13374 /j． issn2095--9389． 2019． 06． 006; http: / /journals． ustb． edu． cn 圆坯凝固末端电磁搅拌作用下的流动与传热行为 李少翔1) ，王 璞1) ，兰 鹏1) ，刘华松1) ，刘麒麟2) ，李树贵2) ，张家泉1)  1) 北京科技大学冶金与生态工程学院，北京 100083 2) 宝山钢铁股份有限公司，上海 201900 通信作者，E-mail: jqzhang@ metall． ustb． edu． cn 摘 要 以特殊钢圆坯连铸为研究对象，建立了研究凝固末端电磁搅拌作用效果的三维耦合数值模型． 利用分段计算模型获 得末端电磁搅拌区域钢液流动与凝固的实际状态，并采用达西源项法处理凝固末端钢液在糊状区的流动，研究了不同电磁搅 拌工艺参数下的电磁场分布及钢液的流动与传热特征． 通过测量搅拌器中心线磁感应强度和铸坯表面温度验证了模型的准 确性． 研究结果表明: 电流强度每增加 100 A，搅拌器中心磁感应强度增加 19. 05 mT，电磁力随着电流强度的增加显著增大． 在 20 ～ 40 Hz 范围，随着电流频率的提高，中心磁感应强度略微下降，但电磁力仍有所增加． 在搅拌器区域，液相穴内的钢液在 切向电磁力的作用下旋转流动，其切向速度随着电流强度和频率的增加而变大． 末端电磁搅拌可促进钢液在圆坯径向的换 热，随着电流强度和频率的提高，铸坯中心轴线上的钢液温度降低，同时末端搅拌位置处的中心固相分率增加． 关键词 圆坯连铸; 凝固末端电磁搅拌; 电磁场; 糊状区流动; 传热 分类号 TF777. 4 收稿日期: 2018--11--30 基金项目: 国家自然科学基金资助项目( U1860111) ; 北京科技大学本科教育教学改革项目( JG2017M11) Melt flow and heat transfer at the crater end of round billet continuous casting using final electromagnetic stirring LI Shao-xiang1) ，WANG Pu1) ，LAN Peng1) ，LIU Hua-song1) ，LIU Qi-lin2) ，LI Shu-gui2) ，ZHANG Jia-quan1)  1) School of Metallurgical and Ecological Engineering，University of Science and Technology Beijing，Beijing 100083，China 2) Baoshan Iron ＆ Steel Co． ，Ltd． ，Shanghai 201900，China Corresponding author，E-mail: jqzhang@ metall． ustb． edu． cn ABSTＲACT Final electromagnetic stirring ( F--EMS) is widely used in the billet and bloom continuous casting process because it ef￾fectively improves the as-cast quality． Numerous industrial trials on F--EMS have been conducted; however，the real melt flow and heat transfer characteristics at the crater end remain unclear． In this study，based on a round billet special steel continuous casting process， a coupled three-dimensional numerical model was developed to describe the F--EMS phenomenon． The flow and solidification behavior of the melt in the F--EMS region were obtained by a segmentation calculation model，and the Darcy source term method was employed to suppress the velocity within the mushy region． The effect of stirring current intensity and frequency on the electromagnetic field，melt flow，and heat transfer was investigated numerically． The model was validated using the measured data of magnetic flux density in the stirrer center and the strand surface temperature． According to the simulation results，with every 100 A increase in the current intensi￾ty，the maximal magnetic flux density increases by 19. 05 mT． The electromagnetic force significantly increases with the increase in cur￾rent intensity． With the increase in current frequency within 20--40 Hz，the magnetic flux density decreases slightly，whereas the elec￾tromagnetic force increases． Moreover，a swirling flow field in the stirrer region is observed under the rotary electromagnetic force，and the tangential velocity of melt increases with the increase in current intensity and frequency． Additionally，the swirling flow enhances the local melt heat transfer at the radial direction of the round strand． As the current intensity and frequency increase，the temperature of the melt in the liquid core decreases，and the center solid fraction at the F--EMS-implemented position increases accordingly．