GCr15钢大方坯结晶器电磁搅拌工艺参数优化研究

摘要：为明确不同电磁搅拌条件对结晶器内钢液流动、传热行为的影响规律,对现场大方坯连铸结晶器电磁搅拌工艺参数的配置提供依据,采用ANSYS Fluent及Maxwell研究了320mm×280mm断面GCr15高碳轴承钢连铸过程中结晶器电磁搅拌工艺参数对结晶器内钢液温度场、磁场特性、注流冲击深度及液面波动的影响规律。研究结果表明,在M-EMS作用下,结晶器内钢液温度的耗散明显优于无电磁场作用工况,有利于改善结晶器内温度均匀性。注流的冲击深度随电流强度的增大而降低,而频率改变对钢液冲击深度影响不明显。当电磁搅拌电流强度一定时,随着搅拌频率增加,液面波动趋于平缓;当搅拌频率一定时,随着电流强度增加,液面波动变剧烈。对于320mm×280mm断面GCr15高碳轴承钢不同工艺进行工业试验,只改变结晶器电磁搅拌参数,从300A/2Hz调整到350A/3Hz,铸坯横截面中心碳偏析指数从1.06降低到1.01,铸坯纵截面中心碳偏析指数的平均值从0.98升至0.99,适合该钢种结晶器电磁搅拌工艺参数为350A/3Hz。

Research on optimization of electromagnetic stirring process parameters of GCr15 steel bloom mold

Abstract：In order to clarify the influence of different electromagnetic stirring conditions on the flow and heat transfer behavior of molten steel in the mold, a basis for the configuration of the electromagnetic stirring process parameters of the on site bloom continuous casting mold was provided. ANSYS Fluent and Maxwell were used to study the influence of electromagnetic stirring process parameters of mold on temperature field, magnetic field characteristics, injection flow impact depth and liquid level fluctuation of molten steel in mold during continuous casting of 320mm×280mm GCr15 high carbon bearing steel. The results show that under the action of M-EMS, the temperature dissipation effect of molten steel in mold is obviously better than that of without electromagnetic field, which is beneficial to improve the temperature uniformity. The impact depth of injection flow decreases with the increase of current intensity, while the change of frequency has no obvious effect on the impact depth of liquid steel. When the current intensity is constant, the fluctuation of liquid level tends to be gentle with the increase of frequency. When the stirring frequency is constant, the liquid level fluctuates violently with the increase of current intensity. For the industrial test of GCr15 high carbon bearing steel with 320mm×280mm section by different processes, only the electromagnetic stirring parameters of the mold were changed from 300A/2Hz to 350A/3Hz. the center carbon segregation index of the billet cross section decreases from 1.06 to 1.01, and the mean value of the center carbon segregation index of the longitudinal section increases from 0.98 to 0.99. The electromagnetic stirring process parameters for the steel mold are 350A/3Hz.