Development and application of final permanent magnet stirring during continuous casting of high carbon rectangular billet

Abstract

Production of continuously cast high carbon steel that very low center macrosegregation is an important object in meeting high quality requirements. Apart from the widely known methods of reducing macrosegregation during continuous casting, final permanent magnet stirring (FPMS) provides an alternative for producing steel with low macrosegregation. The permanent magnet stirring featuring with low power dissipation and high intensity of magnetic field, which is suitable for final stirring conditions. In the present research, a three-dimensional unsteady coupled mathematical model based on the electromagnetic field analysis software Opera-3D and the flow field software Fluent has been developed to analysis the magnetic flux density, the electromagnetic force and the molten steel flow under different stirring frequencies of FPMS. The calculated results in the residual liquid pool show that the center magnetic flux density is nearly invariable equals to 1 335 Gs, the maximum electromagnetic force increases from 12 kN/m3 to 59 kN/m3 and the maximum tangential velocity in the width direction various form 0.09 m/s to 0.45 m/s as the stirring frequency increases from 1 Hz to 5 Hz. The industrial trials reveal that the FPMS with a stirring frequency of 5 Hz can effectively decrease the centre carbon segregation and improve the final product quality of high carbon steel.