Electric Current Distribution During Electromagnetic Braking in Continuous Casting

Alexander Vakhrushev,Zhongqiu Liu,Yong Tang,Gerald Nitzl,Gernot Hackl,Josef Watzinger,Andreas Ludwig,Abdellah Kharicha,Menghuai Wu

doi:10.1007/s11663-020-01952-3

Abstract

The electromagnetic brake (EMBr) is a well-known and widely applied technology for controlling the melt flow in the continuous casting (CC) of the steel. The effect of a steady (DC) magnetic field (0.31 T) in a CC mold is numerically studied based on the GaInSn experiment. The electrical boundary conditions are varied by considering a perfectly insulating/conductive mold or the presence of a conductive solid shell, which is experimentally modeled by 0.5 mm brass plates. An intense current density (up to 350 kA/m2) is induced by the EMBr magnetic field in the form of loops. The electric current loop tends to close either inside the liquid bulk or through the conductive solid. Based on the character of the induced current loop closures, the turbulent flow is affected as follows: (i) it becomes unstable in the insulated mold, forming 2D self-inducing vortex structures aligned with the magnetic field; (ii) it is strongly damped for the conductive mold; and (iii) it exhibits transitional behavior with the presence of a solid shell. The application of the obtained results for the real CC process is discussed and validated.

Highlights

CONTINUOUS casting (CC) technology is a constantly growing and developing branch of steel casting
They are compared with the reference results for the melt flow (Case MF, Table I) without electromagnetic brake (EMBr)
Turbulence Effects under the Applied Magnetic Field. As it known from the previous work on magnetohydrodynamics of the turbulent flows,[26,30] they are strongly influenced by the applied magnetic field; coherent structures aligned with the applied magnetic field are formed and the flow turbulence is reduced to a quasi-2D state

Summary

Introduction

CONTINUOUS casting (CC) technology is a constantly growing and developing branch of steel casting. More than 95 pct of the casted steel in the world is formed through continuous casting machines. With increasing casting speeds and production rates, more control is desired for the solidification process to increase the quality of the final products. One of the effective technologies to assist the continuous casting is the so-called electromagnetic braking (EMBr). It is Manuscript submitted on January 24, 2020.

Results

Discussion

Conclusion