Numerical Simulation of the Effect of Solidified Shell Conductivity and Billet Sizes on the Magnetic Field with Final Electromagnetic Stirring in Continuous Casting

Coupled with the results of a 2D heat transfer model, a 3D electromagnetic stirring round billet model is developed, which is considered for the difference in the conductivity of solidified shell and molten steel. The electromagnetic field distribution features of the billet and the effect of round billet sizes on the electromagnetic field are investigated. It is found that as the solidified shell conductivity of the & phi;600 mm round billet increases from 7.14 x 10(5) S & BULL;m(-1) to 1.0 x 10(6) S & BULL;m(-1), the magnetic induction intensity decreases and the maximum value of electromagnetic force drops from 7976.26 N & BULL;m(-3) to 5745.32 N & BULL;m(-3). The magnetic induction intensity on the center axis of the stirrer rarely changes in the range of & phi;100-& phi;200 mm. With the increase in the round billet from & phi;300 mm to & phi;600 mm, the magnetic induction intensity and the electromagnetic force on the center axis of the stirrer decrease slowly and then significantly. In the range of 2-8 Hz, as the current strength reaches its maximum, the electromagnetic force can be increased by increasing the current frequency for round billets of & phi;100-& phi;500 mm, while there is an optimal current frequency for round billets larger than & phi;600 mm.