A fully couple flow of molten steel, heat transfer, and solidification in the mold region of a continuous casting round billet under mold electromagnetic stirring (M-EMS) are investigate with computational tools of fluid flow and electromagnetic simulations. A finite element model is employed to simulate the electromagnetic stirrer in the mold and calculate the Lorenz force distribution. The Lorenz forces are applied as a source term in the Navier-Stokes equations of the fluid flow model, which was solved through a finite volume model. The flow pattern produced by the stirrer is mainly rotational, with velocities of 0.37 m s À1 close to the solidifying shell for the higher current. The results indicate that a higher M-EMS current produces a reduction of the temperature in the strand center; a decrease of 42 8C is observed for a current of 350 A/4.25 Hz. The M-EMS also produces a thinner shell close to the stirrer center and a larger region of solid fraction in the billet center.

To investigate the inclusion removal in billets cast under electromagnetic stirring (EMS) influence, a numerical model has been developed to compute the magnetic field, the Lorentz force, the steel flow velocities, and the particle transport within the liquid pool. The electromagnetic field was described by the Maxwell equations and the finite element method was applied using a commercial package. The turbulent fluid flow was described by the Navier‐Stokes equation and by the Reynolds Stress model and the finite volume method was applied using another numerical package. The time average of the Lorentz force was calculated in each element center and this value was applied as a body force in the Navier‐Stokes equation. The magnetic flux density profile was compared with the data obtained in the stirrer of the steel plant. The particle transport model includes the drag force, the buoyancy force and the random walk model, to include the turbulence effects on the particle trajectory. The inclusion removal was calculated and analysed in function of casting speed and stirring current for one size section of mold. The inclusions considered in the calculations have a fixed density and four values of diameter. The numerical results of the electromagnetic model are in agreement with the experimental measurements. A good relationship between the electromagnetic model and the fluid flow model could be shown. An interesting effect is the break of the rotation motion due to the EMS by the jet from the nozzle. The fraction of inclusions removed by the top surface of the mold was improved due to the EMS.