Numerical Modeling of Inclusion Removal in Electromagnetic Stirred Steel Billets

Abstract

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.

Magnetohydrodynamic Phenomena, Fluid Control and Computational Modeling in the Continuous Casting of Billet and Bloom

“…In this context, a centripetal force is not needed to impose on the particle, even though it rotates in the fluid, since the fourth term has already played this role. Turbulence treatment on the interaction of the particle with turbulent eddies in the fluid can be referenced in Trindade et al 23) Due to the random nature in the trajectory calculations resulting from the turbulence treatment, one trajectory cannot be reproduced by another even with all the same computation parameters. However, by injecting a large number of particles through the SEN into the mould, statistic results can give a clear trend to show the percentage of the inclusions which are trapped by the slag layer.…”

Numerical Analysis of Coupled Turbulent Flow and Macroscopic Solidification in a Round Bloom Continuous Casting Mold with Electromagnetic Stirring

“…They also carried out a 3-D coupled numerical simulation of electromagnetic field, fluid flow, and inclusion trajectory. [15] Barna and Javurek et al [16,17] performed a numerical comparison of full coupling and simplified coupling between fluid flow and electromagnetic field in round bloom continuous casting [ with M-EMS. They also set up a model to compute the flow field and inclusion distribution inside the whole strand by using the analytical expression for the electromagnetic force deduced by Spitzer [10] .…”

Numerical Study on the Capture of Large Inclusion in Slab Continuous Casting with the Effect of In-mold Electromagnetic Stirring

“…A few previous studies 11,12,[23][24][25][26][27][28][29][30] have investigated the effect of the electromagnetic field application on the particle behaviors in continuous casting. Researchers mainly paid attention to particle removal during continuous casting.…”

“…Researchers mainly paid attention to particle removal during continuous casting. 11,12,[25][26][27][28][29][30] Few works studied the effect of the electro-magnetic field application on the particle capture during continuous casting. 23,24) Liu Z. et al 23) studied the effects of electromagnetic brake (EMBr) arrangement and magnetic field strength on inclusion transport and entrapment in a slab mold, using a mathematical model coupling flow field, magnetic field and inclusion transport.…”