【作者】 朱佳雨； 杨永坤； 王建立； 王伟安； 王阳； 李小明；

【Author】 ZHU Jiayu;YANG Yongkun;WANG Jianli;WANG Weian;WANG Yang;LI Xiaoming;School of Metallurgical Engineering, Xi’an University of Architecture and Technology;

【机构】 西安建筑科技大学冶金工程学院；

【摘要】 为改善大圆坯结晶器电磁偏心搅拌对Φ500mm和Φ650mm圆坯的负面影响,本文建立了电磁、流动、传热和凝固相耦合的三维数学模型,研究了电磁偏心搅拌对不同断面圆坯内钢液流动和传热的影响。通过将直通型水口改变为四孔水口,从而改善了电磁偏心造成的流场分布不均等现象,并引入对称指数S定量评价了电磁偏心搅拌对不同断面圆坯钢液流场的影响。电磁偏心搅拌通过将来自直通型水口的高速射流发生偏移,进一步影响内外弧流场分布,改用四孔水口后,钢液无法通过水口正下方,有效避免了电磁偏心对射流发生偏移的影响。在电磁偏心搅拌作用下,Φ500 mm和Φ650 mm圆坯内外弧最大温差分别出现在距弯月面1.35m和1.73m处,为63K和26K;凝固坯壳最大差值分别出现在距弯月面1.03m和1.78m处,为11.5mm和5.3mm。改用四孔水口后内外弧坯壳分布几乎一致。Φ500mm圆坯的对称性指数由0.55提升至0.77,极大地提高了钢液流场的均匀性。四孔水口可用于改善电磁偏心搅拌对钢液流场产生的负面影响。更多还原

【Abstract】 To mitigate the adverse impact of eccentric mold electromagnetic stirring(EM-EMS) on Φ500 mm and Φ650mm round blooms, a three-dimensional mathematical model coupling electromagnetic, flow, heat transfer, and solidification was established in this paper. The effect of EM-EMS on the flow and heat transfer of molten steel in round blooms with different cross sections was studied. The uneven distribution of the flow field caused by EM-EMS was improved by changing the straight submerged entry nozzle(SEN) to a four-port SEN. The symmetry index, S, was used to quantitatively assess the effect of EM-EMS on the flow field of round blooms with different sections. EM-EMS can affect the flow field distribution by shifting the high-speed jet from the straight SEN. After changing to a four-port SEN, the molten steel cannot pass right under the nozzle, which effectively avoided the impact of EM-EMS on the jet offset. In the presence of EM-EMS,the maximum temperature difference between the inner and outer arcs of Φ500mm and Φ650mm round bloom appears at 1.35m and 1.73m on the meniscus, respectively, 63K and 26K; the maximum difference of solidified shell appears at 1.03m and 1.78m according to the meniscus, which is 11.5mm and 5.3mm, respectively. After using the four-port SEN, the temperature and the shell distribution on the inner and outer curves for the Φ500mm round bloom were almost the same.The symmetry index of Φ500mm round bloom was increased from 0.55 to 0.77, resulting in a significant enhancement in the uniformity of the flow field. The four-hole nozzle can be used to mitigate the negative impact of EM-EMS on the steel flow field.更多还原