Investigations of the liquid steel flow in slab casters with electromagnetic brakes and round bloom casters with electromagnetic stirring

In the continuous casting of steel the application of electromagnetic fields to modify the flow is steadily increasing. Electromagnetic stirring fields are used to excite a rotary motion in the strand thereby – among other benefits – promoting the columnar to equiaxed transition. In slab casters stationary fields shall break the submerged jets, dampen the turbulent movement and calm the liquid steel flow.
The influence of an electromagnetic brake onto the liquid steel flow is investigated through numerical simulations and experimental work. A 1:10 scale model of a continuous slab caster is built and flow measurements are conducted with Ga68In20Sn12 (Galinstan), a low melting point alloy. The results are then used for the validation of fully coupled numeric simulations, where the flow influences the magnetic field and vice versa.
For round bloom casting with electromagnetic stirring the impact of stirring frequency and stirring field current will be shown. From the results a simple analytical model can be deduced, which describes the average azimuthal velocity close to the wall. When combined with an estimation of the power losses, optimal stirring parameters can be chosen.