Numerical Simulation Research On Flow And Temperature Field Of Liquid Steel In Electromagnetic Brake Mold

Due to the advantages of compact process, small investment and low energy consumption, thin slab casting and direct rolling process has been widely used in the world. Since the casting speed of thin slab casting is high and the cast product ratio of width to thickness is large, the flow velocity of liquid steel in the mold is large, and the flow velocity and temperature fields of liquid steel are nonuniform. It is likely to cause a high inclusion content of cast product, longitudinal surface crack and even breakout. In order to improve cast product quality, electromagnetic brake technology has been adopted in industry to control the flow of liquid steel.Considering the effect of liquid core reduction technique to the flow rate of liquid steel at the inlet boundary, FLUENT software has been used to simulate the flow and temperature fields of liquid steel in the mold. To optimize the flow and temperature fields of liquid steel in the mold, parameters have been analyzed which are the immersion depth of nozzle, casting speed and the inner wall space of nozzle, and optimal parameters have been chosen. Based on the selected parameters, it has been established and coupled that is flow model, heat transfer and solidification model, magnetic field model. Using the coupled model, parameters have been analyzed which are the height of magnetic field and magnetic flux density, and optimal parameters have been chosen achieving the goal of further improving the flow and temperature fields of liquid steel in the mold.The effect of magnetic field is as follows. With the height of magnetic field moving down, the flow velocity of vortex near free surface increases, which is not conducive to maintain a stable free surface. Therefore it had better to select an optimal height. With the increase of magnetic flux density, the effect of electromagnetic brake is more evident. The flow velocity of mainstream in the mold becomes smaller and the impact points of liquid steel towards narrow face almost disappear,the velocity of upward reflux becomes more uniform, moreover the temperature gradient of liquid steel in the mold becomes smaller. However overlarge magnetic flux density would block the reflux of liquid steel near narrow face which is flowing towards free surface. Therefore it had better to select an optimal magnetic flux density.