电磁旋流水口对圆坯结晶器液面波动的控制

在大圆连铸坯生产过程中,过强的结晶器电磁搅拌会造成结晶器液面波动,影响连铸坯的表面和内部质量。将电磁旋流水口技术与结晶器电磁搅拌配合使用,通过调整电磁旋流装置的搅拌方向和电流强度来弱化结晶器电磁搅拌引起的二次流,从而使结晶器液面波动控制在一个较小的范围内。结果显示,当两个电磁装置的搅拌方向相反,电流强度为400 A时,大于±2 mm的液面波动比例由单用结晶器电磁搅拌时的0.62%降至0.13%,在±1 mm～±2 mm范围内的液面波动比例由单用结晶器电磁搅拌时的5.90%降至3.56%。当搅拌方向相同时,对大于±2 mm的液面波动的控制效果不佳。因此,使用与结晶器电磁搅拌方向相反的水口旋流可实现对结晶器液面波动的有效控制。

Liquid level fluctuation in mold controlled by electromagnetic nozzle swirling flow in continuous casting of round bloom

In the continuous casting production of round bloom, vigorous mold electromagnetic stirring (M-EMS) could cause violent liquid level fluctuation in the mold, which affects the surface and internal quality in the bloom. An electromagnetic swirling flow in the nozzle (EMSFN) was applied together with the mold electromagnetic stirrer during the continuous casting. The secondary flow induced by M-EMS was weakened by adjusting the stirring direction and the current intensity of the EMSFN device, so that the liquid level fluctuation in the mold could be controlled within a small range. The results show that when the stirring direction of EMSFN device is opposite and the current intensity is 400 A, the fluctuation proportion more than ±2 mm is decreased from 0.62% to 0.13%, and the fluctuation proportion within ±1 mm to ±2 mm is decreased from 5.90% to 3.56%, compared with the results by using only M-EMS in the same strand. When the stirring direction of EMSFN device is the same, the control effect on the liquid level fluctuation more than ±2 mm is not good. Therefore, the liquid level fluctuation can be controlled by the opposite nozzle swirling flow at certain stirring magnitude.