Study on the Electromagnetic Field, Fluid Flow, and Solidification in a Bloom Continuous Casting Mold by Numerical Simulation

Abstract

Based on the Maxwell's equations and low‐Reynolds number k−ϵ turbulence model, a coupled three‐dimensional numerical model has been developed to describe the electromagnetic field, fluid flow, and solidification in a bloom continuous casting mold with electromagnetic stirring (M‐EMS). The optimum frequency is obtained by calculating the maximum electromagnetic torque of the strand with consideration of mold tube shield effect. The effect of stirring current intensity on the turbulent flow, temperature distribution, and shell growth has been investigated numerically. According to the simulation results, the electromagnetic force with a circumferential distribution on the strand transverse section, and a swirling flow field along the axial direction of the strand are observed in the mold region with the application of M‐EMS. It is shown that the melt maximum swirling flow velocity decreases from 0.420 to 0.226 m s−1 and the flow field changes remarkably when solidification is involved in the model. With the current intensity increasing from 260 to 500 A, the swirling flow intensifies significantly, which prevents the superheated molten steel moving downwards to the liquid core and promotes the superheat dissipation in mold.

Numerical Simulation on Multiple Physical Fields Behaviors in Billet Continuous Casting with Different Stirrer Positions

“…Since the magnetic induction intensity during continuous casting process can not be measured, most of the researchers [8,[10][11][12][13][14] verify their mathematical models of continuous casting process with M-EMS by comparing the calculated and measured magnetic induction intensities without casting steel. Therefore, to verify the validity of the established models, the calculated and measured magnetic induction intensities without casting steel are shown in Figure 2.…”

“…[8][9][10][11][12][13][14][15] Trindade et al [8] reported the inclusion trajectory and removal law by coupling magnetic field, flow field, and particle transport. [8][9][10][11][12][13][14][15] Trindade et al [8] reported the inclusion trajectory and removal law by coupling magnetic field, flow field, and particle transport.…”

“…In addition, the optimum stirring parameters were obtained by plant trials. The studies by Li et al, Ren et al, and Trindade et al [12][13][14][15] proved that the M-EMS promoted the superheat dissipation of molten steel, and the increasing current intensity could further reduce the temperature of molten steel. The results showed that with the increasing current intensity and current frequency, the range of lower circulation zone gradually increased.…”

Initial Transfer Behavior and Solidification Structure Evolution in a Large Continuously Cast Bloom with a Combination of Nozzle Injection Mode and M-EMS

“…Yu and Zhu [8] simulated the flow field, the distribution of the temperature field, and the inclusion trajectory in the round billet, and conducted an industrial test to adjust the stirring parameters of the M-EMS, which significantly improved the shrinkage and surface defects of the strand. Li et al [9,10] established a coupled model of electromagnetic, flow, heat transfer, and solidification under the low Reynolds number model of bloom casting. The electromagnetic field under different stirring parameters was revealed, and it was seen that increasing the current intensity will not only promote superheat dissipation, but also cause slow growth in the region of shell solidification.…”

“…Wall surface: a non-slip wall surface is adopted and the nozzle wall is set to adiabatic. The heat flux boundary condition is applied on the mold zone according to Li [10]:…”