A Numerical Analysis of Molten Steel Flow Under Applied Magnetic Fields in Continuous Casting

  • Yoon, Teuk-Myo (Mechanical Engineering Department, Graduate School of Kyunghee University) ;
  • Kim, Chang-Nyung (College of Mechanical & Industrial System Engineering, Kyunghee University)
  • Published : 2003.12.01

Abstract

Although continuous casting process has highly developed, there still remain many problems to be considered. Specifically, two vortex flows resulting from impingement against narrow walls make a flow field unstable in a mold, and it is directly related to internal and external defects of steel products. To cope with this instability, EMBR (Electromagnetic Brake Ruler) technique has been lately studied for the stability of molten steel flow, and it is revealed that molten steel flow in a mold can be controlled with applied magnetic field. However, it is still difficult to clarify flow pattern in an EMBR caster due to complex correlations among variables such as geometric factors, casting conditions, and the place and the intensity of charged magnetic field. In the present study, flow field in a mold is focused with different conditions of electromagnetic effect. To accurately analyze the case, three dimensional low Reynolds turbulent model and appropriate boundary conditions are chosen. To evaluate the electromagnetic effect in molten steel flow, dimensionless numbers are employed. The results show that the location and the intensity of the applied magnetic field significantly influence the flow pattern. Both impingement and internal flow pattern are changed remarkably with the change of the location of applied magnetic field. It turns out that an insufficient magnetic force yields adverse effect like channeling, and rather lowers the quality of steel product.

Keywords

References

  1. Cha, P. R. and Yoon, J. K., 1999, 'The Effect of a Uniform Direct Current Magnetic Field on the Stability of a Stratified Liquid Flux/Molten Steel System,' Metallurgical and Materials Transactions B, Vol. 31, pp. 317-326 https://doi.org/10.1007/s11663-000-0050-y
  2. Chien, K. Y., 1982, 'Prediction of Channel and Boundary- Layer Flows with a Low Reynolds Number Turbulence Model,' AIAA Journal, Vol. 20, No.1, pp. 33-38 https://doi.org/10.2514/3.51043
  3. Huang, X. and Thomas, B. G., 1998, 'Modeling of Transient Flow Phenomena in Continuous Casting of Steel, Canadian Metallurgical Quarterly,' Vol. 37, pp. 197-212 https://doi.org/10.1016/S0008-4433(98)00025-1
  4. Hwang, Y. S., Cha, P. R., Nam, H. S., Moon, K. H. and Yoon, J. K., 1997, 'Numerical Analysis of the Influences of Operational Parameters on the Fluid Flow and Meniscus Shape in Slab Caster with EMBR,' ISIJ international, Vol. 37, pp. 659-667 https://doi.org/10.2355/isijinternational.37.659
  5. Lai, K. Y. M., Salcudean, M., Tanaka, S. and Guthrie, R, I. L., 1986, 'Mathematical Modeling of Flows in Large Tundish System in Steel Making,' Materials Transactions B, Vol. 17B, pp.449-459
  6. Li, B., Okane, T. and Umeda, T., 1999, 'Modeling of Molten Flow in a Continuous Casting Process Considering the Effects of Argon Gas Injection and Static Magnetic- Field Application,' Metallurgical and Materials Transactions B, Vol. 31B, pp. 1491-1503 https://doi.org/10.1007/s11663-000-0034-y
  7. Park, J. P., Jeong, H. T., Sim, D. J., Chung, J. S., Kim, H. Y. and Jeong, J. Y., 1999, 'The Effect of the Mold Shape on the Surface Quality of Steel Billet with Electromagnetic Casting Technology,' RIST
  8. Seyedein, S. H. and Hasan, M., 1997, 'A Threedimensional Simulation of Coupled Turbulent Flow and Macroscopic Solidification Heat Transfer for Continuous Slab Caster,' Heat Mass Transfer International, Vol. 40, pp.4405-4423 https://doi.org/10.1016/S0017-9310(97)00064-1
  9. Sutton, G. W. and Sherman, A., 1986, 'Engineering Magnetohydrodynamics,' McGraw-Hill, New York, pp. 355-388
  10. Van doormaal, J. P. and Raithby, G. D., 1984, 'Enhancements of the SIMPLE Method for Predicting Incompressible Fluid Flows,' Numer. Heat Transfer, Vol. 7, pp. 147-163 https://doi.org/10.1080/01495728408961817
  11. Zheng, X., Wang, Y., Li, Z. and Jin, J., 2001, 'Numerical Simulation of the Temperature Field on the Electromagnetic Semi-Continuous Casting of slab,' Science and Technology of Advanced Materials 2 https://doi.org/10.1016/S1468-6996(01)00035-3