方坯连铸凝固末端电磁搅拌工艺优化的数值模拟

利用ANSYS和CFX软件建立了描述160mm×160mm方坯连铸凝固末端电磁搅拌过程的数学模型.通过确立钢液黏度与温度的定量关系，考虑凝固时钢液黏度的重要影响，研究了方坯凝固末端糊状区磁场和流场的分布，以及电流强度对凝固前沿钢液最大搅拌速度的影响规律.结果表明:搅拌电流强度每增加100A，铸坯中心磁感应强度增加250×10-4T，切向电磁力增加1933N/m3，最大流速增加69cm/s.现场实验检验结果表明:60#钢凝固末端电磁搅拌器安装位置处液芯半径为344mm，最佳电磁搅拌频率为6Hz，最佳搅拌电流为380A，此时凝固前沿最大流速为165cm/s，铸坯中心碳偏析得到明显改善，中心碳偏析指数为104.

Numerical Simulation for Optimization of F-EMS in Billet Continuous Casting

An F-EMS mathematical model was built for 160 mm×160 mm continuous casting billet by ANSYS and CFX software. With establishing viscosity of the molten steel as a function of temperature, and considering the important effect of molten steel while solidification, the distribution of electromagnetic field and flow field in the mushy zone of the billet and the influence law of maximum flow velocity at the solidification front under various stirring currents were investigated. The calculation results showed that with increasing 100 A of the current intensity, the magnetic intensity, tangential electromagnetic force and flow velocity of molten steel increase 250×10^-4 T, 1933 N/m³ and 6.9 cm/s, respectively. The on-site tests showed that the proper liquid core radius at solidification end of billet for F-EMS is 34.4 mm, and the optimal frequency and current for F-EMS are 6 Hz and 380 A, respectively. With these F-EMS parameters, the maximum flow velocity of molten steel at the solidification front caused by electromagnetic force is 16.5 cm/s and central carbon segregation index in billet is 1.04.