Effect of Electromagnetic Frequency on the Flow Behavior in Mold during Bloom Casting

Xianglong Li,Qi Quan,Deyong Wang,Xingzhi Zhou,Tianpeng Qu,Shaoyan Hu

doi:10.3390/met11111828

Abstract

Considering solidification, a large eddy simulation (LES) model of two-phase flow was established to simulate the thermal–magnetic flow coupled fields inside a jumbo bloom. The magnetic field was calculated based on Maxwell’s equations, constitutive equations, and Ohm’s law. An enthalpy–porosity technique was used to model the solidification of the steel. The movement of the free surface was described by the volume of fluid (VOF) approach. With the effect of electromagnetic stirring (MEMS), the vortices in the bloom tended to be strip-like; large vortices mostly appeared in the injection zone, while small ones were found near the surface of the bloom. It is newly found that even though the submerged entry nozzle (SEN) is asymmetrical about the bloom, a biased flow can also be found under the effect of MEMS. The reason for this phenomenon is because the magnetic force is asymmetrical and transient. A high frequency will reduce the period of biased flow; however, the frequency should not be too high because it could also intensify meniscus fluctuations and thus entrap slag droplets in the mold. The velocity near the solidification front can also be increased with a higher frequency.

Highlights

IntroductionJumbo round blooms are widely used to produce seamless bars, wheels, and tubes
The results reveal that the vectors of the magnetic flux density are almost parallel, rotating periodically in-0.3
4 shows thethe magnetic distribution at the mid-plane of the stirrer.rotatThe results that vectorsflux of density the magnetic flux density are almost parallel, The results reveal that the vectors of the magnetic flux density are almost parallel, rotat-value ing periodically in TB (TB is the reciprocal of the current frequency)

Summary

Introduction

Jumbo round blooms are widely used to produce seamless bars, wheels, and tubes. Continuous casting (CC) is more efficient and has been used to lower costs and increase profits for industrial plants. Many defects such as cavities, segregation, and center porosity may occur in CC, especially as the bloom size increases. There are rarely reports on jumbo round blooms with a diameter larger than 700 mm. It is urgent to gain a deep understanding of the flow characteristics inside jumbo blooms

Objectives

Results

Conclusion