Study on the liquid metal flow field in FC-mold of slab continuous casting

Abstract

The flow pattern and the velocity distribution of a liquid metal in the flow control mold (FC-mold) were investigated with a mercury model by analogy to the molten steel during continuous casting. The velocity measurement was conducted by the ultrasonic Doppler velocimeter (UDV) under various magnetic distributions and flux densities. The impingement intensity and the scouring intensity of the liquid metal to the narrow wall of the mold were calculated based on the measured data, and the influence of the magnetic flux density on the liquid metal flow in the mold was analyzed. The results showed that the surface of the liquid metal became more active when only the lower magnet was assembled, and the surface fluctuation was suppressed when further applying the upper magnetic field. It was indicated that when the upper and lower magnetic flux densities were 0.18 T and 0.5 T, respectively, the optimum conditions could be obtained, under which the free surface fluctuation could be suppressed, and a flow recirculation could rapidly form.

Keywords

FC-mold / Continuous casting / Electromagnetic brake / Magnetic flux intensity

References

[1] Idogawa A, Sugizawa M, Takeuchi S. Control of molten steel flow in continuous casting mold by two static magnetic fields imposed on whole width. Mater Sci Eng A, 1993, A173: 293.

[2] Kariya K, Kitano Y, Kuga M et al (1994) Development of flow control mold for high speed casting using static magnetic fields. In: Steelmaking conference proceedings on iron & steel society, Warrendale, PA, pp 53–58

[3] Hwang Y, Cha P, Nam H. Numerical analysis of the influences of operational parameters on the fluid flow and meniscus shape in slab caster with EMBR. ISIJ Int, 1997, 37(7): 659-667.

[4] Lehman AF, Tallback GR, Kollberg SG et al (1994) Fluid flow control in continuous casting using various configuration of static magnetic fields. In: International symposium on electromagnetic processing materials, ISIJ, Tokyo, pp 372–397

[5] Nagai J, Suzuki K, Kojima S. Steel flow control in a high-speed continuous slab caster using an electromagnetic brake. Iron Steel Eng, 1984, 61: 41-47.

[6] Hanada H. Effect of density difference of molten steels on the mixing in strand pool in the sequential casting of different steel grades with a level DC magnetic field. CAMP-ISIJ, 1999, 12: 830-842.

[7] Zeze M, Tanaka H, Takeuchi E et al (1996) Continuous casting of clad steel slab with level magnetic field brake. In: Steelmaking conference proceedings, Pittsburgh, pp 225–230

[8] Thomas BG, Zhang LF. Mathematical modeling of fluid flow in continuous casting. ISIJ Int, 2001, 41: 1181-1193.

[9] Gupta D, Chakraborty S, Lahiri AK. Asymmetry and oscillation of the fluid flow pattern in a continuous casting mould: a water model study. ISIJ Int, 1997, 37: 654-658.

[10] Takatani K, Tanizawa Y, Mizukami H. Mathematical model for transient fluid flow in a continuous casting mold. ISIJ Int, 2001, 41: 1252-1261.

[11] Takatani K, Nakaii K, Kasai N. Analysis of heat transfer flow in the continuous casting mold with electromagnetic brake. ISIJ Int, 1989, 29: l063-l1068.

[12] Moon KH, Shin HK, Kim BJ. Flow control of molten steel by electromagnetic brake in the continuous casting mold. ISIJ Int, 1996, 36: 201-203.

[13] Chaudhary R, Thomas BG, Vanka SP. Effect of electromagnetic ruler braking (EMBr) on transient turbulent flow in continuous slab casting using large eddy simulations. Metall Mater Trans B, 2012, 43B: 532-553.

[14] Najjar FM, Thomas BG, Hershey DE. Numerical study of steady turbulent flow through bifurcated nozzles in continuous casting. Metall Mater Trans B, 1995, 26: 749-765.

[15] Honeyands T, Herbertson J. Flow dynamics in thin slab caster moulds. Steel Res, 1995, 66: 287-293.

[16] Odenthal HJ, Lemanowicz I, Gorissen R. Simulation of the submerged energy nozzle-mold water model system using laser-optical and computational fluid dynamics methods. Metall Mater Trans B, 2002, 33: 163-172.

[17] Singh R, Thomas BG, Vanka SP. Effects of a magnetic field on turbulent flow in the mold region of a steel caster. Metall Mater Trans B, 2013, 44: 1201-1221.

[18] Singh R, Thomas BG, Vanka SP. Large eddy simulations of double-ruler electromagnetic field effect on transient flow during continuous casting. Metall Mater Trans B, 2014, 45: 1098-1115.

[19] Cho SM, Kim SH, Thomas BG (2014) Transient fluid flow during steady continuous casting of steel slabs. Part I. Measurements and modeling of two-phase flow. Part II. Effect of double-ruler electro-magnetic braking. ISIJ Int 54:845–854 and 855–864

[20] Timmel K, Miao X, Lucas D. Experimental and numerical modelling of the steel flow in a continuous casting mould under the influence of a transverse DC magnetic field. Magnetohydrodynamics, 2010, 46: 437-448.

[21] Timmel K, Eckert S, Gerberth G. Experimental investigation of the flow in a continuous-casting mold under the influence of a transverse, direct current magnetic field. Metall Mater Trans B, 2011, 42B: 68-80.

[22] Miao XC, Timmel K, Lucas D. Effect of an electromagnetic brake on the turbulent melt flow in a continuous-casting mold. Metall Mater Trans B, 2012, 43B: 954-972.

[23] Yu Z, Zhang ZQ, Ren ZM. Study on the fluid flow in slab continuous casting mold with electromagnetic brake. Acta Metall Sin, 2010, 46: 1275-1280.

[24] Signal Processing SA (2008) User’s manual for DOP2000 Model 2125/2032. Software: 4.02 Revision: 2