| A variety of defects, such as shrinkage, porosity, segregation, inclusion etc, are inevitable during the process of ingot solidification. In order to improve the quality and increase the yield of the ingot, the technology of electromagnetic compensation is proposed based on electromagnetic thermal and force effect to liquid steel, and the common problems that happen to riser supplement shrink. Slab ingot is used as the research object and select 50 % Bi-26.7 % Pb-13.3 % Sn-10 % Cd alloy as the simulacrum of liquid steel in this paper. The magnetic field distribution inter the simulacrum of liquid steel is studied by experiments and numerical simulations.Meanwhile, the influence of coil current, power frequency and the relative position of the coil on the magnetic field distribution are also studied. In addition, the thermal response in the process of electromagnetic compensation is studied. The following conclusions are drawn:(1)The magnetic induction intensity along Z direction of the simulacrum of liquid steel is increased at first and then decreased. The magnetic induction intensity peak appears in the center of the simulacrum of liquid steel. The magnetic induction intensity at the corner is higher than other positions. The magnetic induction intensity of the narrow side center and broad side center is a little lower relatively, the magnetic induction intensity of the center position is the minimum. The magnetic induction intensity along the direction of X and Y axis are both high at ends and low in the middle, the magnetic induction intensity is symmetrical in the center.(2) With the increase of intense of the coil current, the magnetic induction intensity of the liquid steel is obviously enhanced but its uniformity is reduced; With the increase of the power frequency, the magnetic induction intensity of the central position decreases, the decrease amplitude increases, and the magnetic induction intensity of the central magnetic field increases and the increases amplitude decreases;With the induction coil moving up, the magnetic induction intensity peak is also shifted, but its peak value is slightly lower. Taking the electromagnetic thermal effect,the electromagnetic force effect and the requirements of the experimental equipment and other factors into consideration, this paper finally propose that coil current150A~200A, power frequency 2000 Hz, the coil move up to the height of about165 mm is suitable for the process of ingot electromagnetic compensation.(3)The magnetic induction intensity simulation results are slightly higher than those of actual measurement results, finally the deviation between simulation and measured results are 6.04% and 16.32% respectively, which can meet the requirementof engineering analysis. It shows that the simulation of the application feasibility can also be used in actually liquid steel internal magnetic field distribution characteristics and provide very reliable theoretical guide.(4) With the increase of intense of the coil current, the overall heating efficiency of simulacrum of liquid steel increases gradually. But there is a large difference for the heating efficiency, when the coil current changed from 150 A to200A, the maximum of heating efficiency increase reach the highest; With the power frequency increases, the overall heating efficiency also be increased, but its increase not be very obvious.(5)With the increase of magnetic induction intensity, the temperature response speed is faster, and slower on the contrary. The surface temperature of the simulacrum of liquid steel is mainly influenced by induction heating and its internal temperature increases cased mainly because of heating transfer, the positions internal temperature response speed show less differences; With the increase of the coil current intensity,the internal temperature response speed of the simulacrum of liquid steel can also be increased; Under the action of the same coil current, the temperature response rate of the steel liquid is obviously faster than that before melting. |
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