在不同工业实验条件下，研究了电磁旋流水口技术对小方坯的凝固组织和C、S元素宏观偏析特征的影响规律，并与结晶器电磁搅拌所得结果相比较。结果表明，仅用电磁旋流水口技术，在电流频率为50 Hz时，随着电流强度由200 A升至600 A，等轴晶逐渐增多，而中心偏析严重程度先减轻后加重，在凝固组织以细小柱状晶为主时出现最优值。研究还表明，可以通过调整电磁旋流装置的电流参数来改变浸入式水口内钢水的旋流强度，进而获得不同凝固组织形貌和宏观偏析严重程度的铸坯。在本实验条件下，当装置的电流参数达到一定值后，电磁旋流水口技术在提高铸坯质量方面可以达到与结晶器电磁搅拌相同甚至更优的效果。

During continuous casting production of square billet, the quality of steel billet is determined by equiaxed grain rate and defect grade of centerline segregation. The application of mold electromagnetic stirrer (M-EMS) can improve the quality, but it also brings some negative effects. Some researchers have attempted to make a swirling flow generated in submerged entry nozzle keep rotating in the mold to replace M-EMS. In this work, the influence of electromagnetic swirling flow in nozzle (EMSFN) on morphology of solidification structure and macrosegregation characteristics of carbon and sulfur was studied under different industrial test conditions, and the results were compared with those obtained by M-EMS. The results show that when the current frequency of EMSFN device is 50 Hz, with the current intensity increasing from 200 A to 600 A, the quantity of equiaxed grains increases gradually, while the severity of centerline segregation decreases first and then increases. The optimum value of centerline segregation was obtained when solidification structure was dominated by fine columnar crystals. Therefore, the swirling flow intensity of molten steel in submerged entry nozzle can be changed by adjusting the current parameters of EMSFN device, and thus the billets with different morphology of solidification structure and severity of macrosegregation can be obtained. Under the experimental condition, when the current parameters of EMSFN device reach certain values, EMSFN can achieve the same or even better effect as M-EMS in improving the quality of billet.