Influence of Dual-Channel Induction Heating Coil Parameters on the Magnetic Field and Macroscopic Transport Behavior in T-Type Tundish

Abstract

For the purpose to produce bloom castings by a six-strand T-type tundish with dual-channel induction heating (IH) instrumentation, a three-dimensional electromagnetic-flow-heat transfer and solute transport model was established without changing the body structure for the tundish, and the effect of induction coil parameters on the metallurgical behavior of the tundish was studied. The accuracy of the model was verified by comparing the model predictions with the diffusion of tracer in the isothermal physics experiment. The results show that when the coil was placed vertically inside the channel, the downward eccentricity of the electromagnetic force at the channel exit caused by the skin effect and the proximity effect promoted the downward flow of the heated high-temperature molten steel. However, when the coil was placed horizontally under the channel, the eccentric upward electromagnetic force at the channel exit pushed the liquid steel to flow upward. After heating for the 1800 seconds under 800 kW power, compared with the vertical placement of the coil, the horizontal placement can reduce the dead zone ratio, average residence time standard deviation and maximum temperature difference of each strand by 0.88 pct, 34.5 seconds and 0.73 K, respectively, and under 1000 kW by 1.31 pct, 64.37 seconds and 0.51 K. In general, the horizontal placement of the coil with the power of 1000 kW is not only beneficial to reduce the dead zone ratio and improve the flow consistency of the blooms for better surface quality, but also helpful to compensate the heat loss of the tundish and improve the temperature consistency accordingly. It suggested that reasonable IH coil parameters for realization of low superheat degree casting is beneficial to improve the internal quality of the blooms and the stability of their final products.