Deflection of steel dendrite growing in the fluid flow driven by electromagnetic stirrer

In order to evaluate the flow velocity of molten steel driven by electromagnetic stirrer in the mold, not only deflection mechanism of dendrite due to fluid flow but also fluid dynamics promoted by Lorentz force have been taken into account. Deflection angle of dendrite in cross section have been analyzed in various steels which have been cast with various width and promotive forces. The relation between deflection angle and promotive force is not well correlated (correlation factor: 0.63). It is found from the numerical analysis of fluid dynamics that the flow velocity increases with increasing width of stab, at a constant promotive force. Thus, promotive forces are normalized with respect to width. Since the deflection angle of steel dendrite is affected by carbon content, experimental data on deflection angle are also modified by carbon content. The relation between normalized promotive force and modified deflection angles is then quite well correlated (correlation factor: 0.97). Since the Lorentz force is a body one, the flow velocity (U_s) can be simply derived. The ratio between flow velocity calculated from modified deflection angle and U_s is approximately 0.4, which may be constant with usual casting condition of slab. This indicates that 60% of imposed electromagnetic force disappears due to the interaction of 3D flow, due to the interference between submerged entry nozzle etc. To estimate the flow velocity, it is important to take the effect of carbon content on deflection angle into consideration.