Influence of electromagnetic braking on metallurgical behavior in thin plate crystallization
LI Xuekai1,2, ZHANG Yanchao1,2, ZHANG Caijun1,2, XIAO Pengcheng1,2, ZHU Liguang1,3
1. School of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063000, Hebei, China; 2. Hebei High Quality Steel Continuous Casting Engineering Technology Research Center, Tangshan 063000, Hebei, China; 3. School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050000, Hebei, China
Abstract：In order to further improve the application effect of multi-module electromagnetic braking system in the process of efficient continuous casting,the FTSC thin slab mold of a steel mill and the new multi-module continuous electromagnetic braking (MM-EMB) system were taken as the prototype,and the characteristics of the flow field inside the mold and the fluctuation degree of steel slag interface were taken as the evaluation criteria. By means of numerical simulation,the multi-physical field coupling calculation of the mold flow field under different electromagnetic conditions was carried out. The influence law of different coil combinations in the multi-module continuous electromagnetic braking system on the characteristics of the flow field in the thin slab continuous casting mold was mainly revealed when different current intensities were applied to the electromagnetic braking system under the condition of high pulling speed of 6 m/min. The results showed that combined with the structural characteristics of the five-hole water outlet,the electromagnetic braking (MM-EMB) system can divide the five groups of coils into two groups of control units according to its scope of operation. The upper control unit contains two groups of coils,and the main scope is the reflux area of the liquid steel flow field. When the current applied by the two groups of coils increases from 400 A to 1 000 A,It can effectively reduce the impact velocity of molten steel on steel slag interface and reduce the fluctuation of steel slag interface. The lower control unit contains three groups of coils,which are mainly used to stabilize the flow of the lower reflux in the mold. When the current intensity of the three groups of coils increases to 800 A,the vortex center and the impact point on the building surface decrease significantly,and the intensity and range of the lower reflux are effectively controlled. When the two groups of control units are acted on the liquid steel flow field of the mold,and the coil current strength of the lower control unit is 800 A,the current value of the two groups of coil of the upper control unit is 800 A to achieve the best braking effect. The results of numerical simulation were applied to the industrial experiment. Through the field data tracking,the slag inclusion rate and crack rate of the casting billet were further reduced. The application of numerical simulation method provides the theoretical basis and technical support for the further optimization of the mold flow field in the multi-module continuous electromagnetic braking system.
[1] 殷瑞钰,张慧. 新形势下薄板坯连铸连轧技术的进步与发展方向[J]. 钢铁,2011,46(4):1.(YIN R Y,ZHANG H. Progress and development direction of thin slab continuous casting and continuous rolling technology under the new situation[J]. Iron and Steel,2011,46(4):1.) [2] 毛新平,高吉祥,柴毅忠. 中国薄板坯连铸连轧技术的发展[J]. 钢铁,2014,49(7):49.(MAO X P,GAO J X,CHAI Y Z. Development of continuous casting in China[J]. Iron and Steel,2014,49(7):49.) [3] 王皓,王国连,马硕,等. MCCR产线低碳钢高拉速技术研究与应用[J]. 中国冶金,2022,32(12):88. (WANG H,WANG G L,MA S,et al. Research and application on high casting speed technology of low-carbon steel MCCR line[J]. China Metallurgy,2022,32(12):88. ) [4] 朱苗勇. 高拉速连铸过程传输行为特征及关键技术探析[J]. 钢铁,2021,56(7):1. (ZHU M Y. A study of transport phenomena and key technologies for high-speed continuous casting of steel[J]. Iron and Steel,2021,56(7):1. ) [5] 朱苗勇. 新一代高效连铸技术发展思考[J]. 钢铁,2019,54(8):21.(ZHU M Y. Thinking on the development of a new generation of efficient continuous casting technology[J]. Iron and Steel,2019,54(8):21.) [6] 罗衍昭,何文远,王少军,等. 2.05 m/min高拉速低碳钢FC控流结晶器的应用[J]. 连铸,2022(4):72. (LUO Y Z,HE W Y,WANG S J,et al. Application of fluid control mold on low carbon steels at 2.05 m/min high speed slab continuous casting[J]. Continuous Casting,2022(4):72. ) [7] 马明,郑旭涛,喻尧,等. EMBr对高拉速薄板坯钢水动态行为影响的模拟[J]. 连铸,2022(5):17.(MA M,ZHENG X T,YU Y,et al. Simulation of the influence of EMBr on the dynamic behavior of high tensile slab[J]. Continuous Casting,2022(5):17.) [8] LI B,OKANE T,UMEDA T. Modeling of molten metal flow in a continuous casting process considering the effects of argon gas injection and static magnetic-field application[J]. Metallurgical and Materials Transactions B,2000,31(6):1491. [9] TIMMEL K,ECKERT S,GERBETH G. Experimental investigation of the flow in a continuous-casting mold under the influence of a transverse,direct current magnetic field[J]. Metallurgical and Materials Transactions B,2011,42(1):68. [10] 任博群,宝艳明,李壮,等. 电磁制动结晶器内电磁参数对钢液流动行为影响数值模拟[J]. 辽宁石油化工大学学报,2021,41(6):72.(REN B Q,BAO Y M,LI Z,et al. Numerical simulation of the influence of electromagnetic parameters on the flow behavior of steel fluid[J]. Journal of Liaoning Petrochemical University,2021,41(6):72.) [11] ZHAO B,THOMAS B G. Transient fluid flow and superheat transport in continuous casting of steel slabs[J]. Metallurgical and Materials Transactions B,2005,36B:801. [12] WANG Y F,ZHANG L F. Fluid flow-related transport phenomena in steel slab continuous casting strands under electromagnetic brake[J]. Metallurgical and Materials Transactions B,2011,42(6):1319. [13] CUKIERSKI K,THOMAS B G. Flow control with local electromagnetic braking in continuous casting of steel slabs[J]. Metallurgical and Materials Transactions B,2008,39(1):94. [14] LEI S W,ZHANG J M. Study of molten steel flow and inclusions motion behavior in the solidification processes for high speed continuous casting slab by numerical simulation[J]. Transactions of the Indian Institute of Metals,2016,69(6):1193. [15] LI B K,FUMITAKA T,张维维. 电磁制动对薄板坯连铸结晶器涡流的影响[J]. 鞍钢技术,2009(2):51.(LI B K,FUMITAKA T,ZHANG W W. Effect of electromagnetic braking on vortex current of thin slab[J]. Angang Technology,2009(2):51.) [16] GARCIA-HERNANDEZ S,MORALES R D,TORRES-ALONSO E. Effects of electromagnetic brake,mold curvature and slide gate on fluid flow of steel in a slab mold[J]. Steel Research International,2009,80(11):816. [17] CHEN W,REN Y. Large eddy simulation on the fluid flow,solidification and entrapment of inclusions in the steel along the full continuous casting slab strand[J]. JOM,2018,70(12):2968. [18] LIU Z Q,LI B K. Modeling of quasi-four-phase flow in continuous casting mold using hybrid eulerian and lagrangian approach[J]. Metallurgical and Materials Transactions B,2017,48(2):1248. [19] 张朝阳,柴清风,刘增勋,等. 180 mm×505 mm板坯连铸结晶器流场的模拟研究[J]. 热加工工艺,2022,51(15):74.(ZHANG C Y,CHAI Q F,LIU Z X,et al. Simulation study of the flow field of 180 mm×505 mm slab continuous casting crystal device[J]. Thermal Working Process,2022,51(15):74.) [20] GUPTA D,LAHIRI A K. A water model study of the flow asymmety inside a continuousslab casting mold[J]. Metallurgical and Materials Transactions B,1996,27B(10):757. [21] 朱立光,张利民,王杏娟,等.漏斗形结晶器液面流场物理试验与数值模拟分析[J]. 连铸,2021(6):2.(ZHU L G,ZHANG L M,WANG X J,et al. Physical test and numerical simulation analysis of liquid surface flow field of funnel-shaped crystallizer[J]. Continuous Casting,2021(6):2.) [22] 张然,许琳,韩泽峰,等. 立式组合电磁制动对CSP结晶器内钢液流动及偏流控制[J]. 中国冶金,2022,32(1):44.(ZHANG R,XU L,HAN Z F,et al. Vertical combined electromagnetic brake on steel flow and deflection control in CSP crystallization[J]. China Metallurgy,2022,32(1):44.) [23] 王伟,朱立光,张彩军,等. 180 mm×610 mm板坯连铸结晶器内流场水模型及数值模拟[J]. 中国冶金,2020,30(2):46.(WANG W,ZHU L G,ZHANG C J,et al. Water model and numerical simulation of 180 mm×610 mm slab continuous casting crystal device[J]. China Metallurgy,2020,30(2):46.) [24] 薛瑞,张燕超,张彩军,等. 160 mm×160 mm小方坯连铸结晶器内流场数值模拟[J]. 中国冶金,2020,30(1):51.(XUE R,ZHANG Y C,ZHANG C J,et al. Numerical simulation of internal flow field of 160 mm×160 mm billet[J]. China Metallurgy,2020,30(1):51.)
2023, Vol. 58 
