通过物理模拟实验研究板坯连铸流动控制结晶器(flow control mold II, 即FC Mold II)电磁制动过程中, 磁场强度和分布对结晶器内金属液流动的影响规律. 实验中, 以水银为模拟工质, 在模型拉速为0.41, 0.52和0.82 m/min(分别相当于生产拉速1.00, 1.30和2.00 m/min), 电磁制动的上区磁场强度B1=0.18, 0.36和0.50 T, 下区磁场保持B2=0.50 T不变的匹配(组合)条件下, 考察结晶器(模型)内的水银流态和流速分布, 并以此分析上、下区磁场强度匹配(组合)对水口出流、液面流动以及结晶器窄面模壁所受冲刷等的影响规律. 结果表明, 在上述拉速条件下, FC Mold II电磁制动的上、下区磁场强度匹配关系, 分别取B1/B2=0.36, 0.72和1.00时, 结晶器中金属液的制动效果最好.
Electromagnetic brake (EMBr) affects the flow field in mold during the slab continuous casting process. Flow control mold II (FC Mold II) has been developed to resolve the defects of the third generation (flow control mold) of EMBr which the braking effect on meniscus is too strong to make the surface flow excessively stabilize and it would be prone to freezing and related defects. To gain a fundamental understanding of FC Mold II, a mercury physical model was developed to investigate the influence of the magnetic field intensity match on metal flow in FC Mold II based on the\linebreak 1350 mm×230 mm slab continuous casting process in a factory. The flow regime and velocity distribution in mold were measured by ultrasound Doppler velocimeter (UDV) with the maximum magnetic field intensity of the upper pair of magnetic poles B1=0.18, 0.36 and 0.50 T respectively and the maximum magnetic field intensity of the down pair of magnetic poles B2=0.50 T, while the mold casting speed is 0.41, 0.52 and 0.82 m/min respectively corresponding to the practical casting speed 1.00, 1.30 and 2.00 m/min respectively. The influences of the magnetic field intensity match on the flow discharged from the nozzle, the flow near the meniscus and the washing intensity to the mold narrow wall were analyzed and studied. The results showed that, when the magnetic field intensity match of the upper and the lower pair of magnetic poles B1/B2≤1, with the continuous casting speed increasing, the value of B1/B2 should increase in order to get an ideal braking effect. The value of B1/B2 should be 0.36, 0.72 and 1.00 respectively when the model casting speed is 0.41, 0.52 and 0.82 m/min respectively. The increasing of the intensity of the magnetic field reduces the “flow passage” effect caused by EMBr, and is conducive to the formation of the plug flow under the electromagnetic braking region.
[1] Ttimmel K, Eckert S, Gerbeth G. Metall Mater Trans, 2011; 42B: 68
[2] Cukierski K, Thomas B G. Metall Mater Trans, 2008; 39B: 94
[3] Li B K, Tsukihashi F. ISIJ Int, 2006; 26: 1833
[4] Yu Z, Zhang Z Q, Ren ZM, Lei Z S, Deng K. Acta Metall Sin, 2010; 46: 1275
(于湛, 张振强, 任忠鸣, 雷作胜, 邓康. 金属学报, 2010; 46: 1275)
[5] Harada H, Toh T, Ishii T, Kaneko K, Takeuchi E. ISIJ Int, 2001; 41: 1236
[6] Hwang Y S, Cha P R, Nam H S, Moon K H, Yoon J K. ISIJ Int, 1997; 37: 659
[7] Mao B. Contin Cast, 1999; 6: 37
(毛斌. 连铸, 1999; 6: 37)
[8] Thomas B G, Mika L J, Najjar F M. Metall Mater Trans, 1990; 21B: 387
[9] Lei H, Xu G J, He J C. Chem Eng Technol, 2007; 30: 1650
[10] Garcia–Hernandez S, Morales R D, Torres–Alonso E. Ironmaking Steelmaking, 2010; 37: 360
[11] Zhong D Q, Yu L W. ISIJ Int, 2004; 44: 100
[12] Choi S L, Ryu K J, Park H S. Met Mater Int, 2002; 8: 527
[13] Wang Y F, Zhang L F. Metall Mater Trans, 2011; 42B: 1319
[14] Chaudhary R, Thomas B G, Vanka S P. Metall Mater Trans, 2012; 43B: 532
[15] Klaus T, Sven E, Gunter G. Metall Mater Trans, 2011; 42B: 68
[16] Qian Z D, Wu Y L. ISIJ Int, 2004; 44: 100
[17] Yu H Q, Wang B F, Li H Q, Li J C. J Mater Process Technol, 2008; 202: 179
[18] Che Z H, Wang E G, Lei H, He J C. Iron Steel, 2008; 43(8): 25
(陈芝会, 王恩刚, 雷洪, 赫冀成. 钢铁, 2008; 43(8): 25)
[19] Li B K, Okane T, Umeda T. Metall Mater Trans, 2000; 31B: 1491
[20] Timmel K, Eckert S, Gerbeth G, Stefani F, Wondrak T.ISIJ Int, 2010; 50: 1134
[21] Wang M, Jia H, Zhang Z Q, Deng K. Shanghai Met, 2011; 33(6): 41
(王 敏, 贾 皓, 张振强, 邓 康. 上海金属, 2011; 33(6): 41)
[22] Jia H, Wang M , Zhang Z Q, Deng K, Lei Z S, Ren Z M. Shanghai Met, 2012; 34: 53
(贾 皓, 王 敏, 张振强, 邓 康, 雷作胜, 任忠鸣. 上海金属, 2012; 34: 53)
[23] Brito D, Nataf H C, Cardin P, Aubert J, Masson J P. Exp Fluids, 2001; 31: 653
[24] Yu Z, Lei Z S, Jia H H, Jin X L, Ren Z M, Deng K, Zhong Y B. Shanghai Met, 2007; 29(2): 54
(于湛, 雷作胜, 贾洪海, 金小礼, 任忠鸣, 邓康, 钟云波. 上海金属, 2007; 29(2): 54)
[25] Wang Y, Zhang Z Q, Yu Z, Jia H, Deng K, Lei Z S, Ren Z M. Acta Metall Sin, 2011; 47: 1285
(王寅, 张振强, 于 湛, 贾 皓, 邓 康, 雷作胜, 任忠鸣. 金属学报, 2011; 47: 1285)
