Effects of operating parameters on the flow field in slab continuous casting molds with narrow widths

Abstract

Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting (CC) molds with narrow widths for the production of automobile exposed panels. Reasonable agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC process. The simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the mold. Increases in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation zone. The flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min⁻¹ and casting speed of 1.7 m·min⁻¹. Under the present experimental conditions, the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.

Keywords

flow field / rod deflection method / continuous casting / narrow width / numerical simulation / operating parameters

References

[1] Wang XH. Non-metallic inclusion control technology for high quality cold rolled steel sheets. Iron Steel, 2013, 48(9): 1.

[2] 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(7): 654.

[3] Cho SM, Thomas BG, Kim SH. Effect of nozzle port angle on transient flow and surface slag behavior during continuous steel-slab casting. Metall. Mater. Trans. B, 2019, 50(1): 52.

[4] Liu ZQ, Li BK, Jiang MF. Transient asymmetric flow and bubble transport inside a slab continuous-casting mold. Metall. Mater. Trans. B, 2013, 45, 675.

[5] Zhang T, Luo ZG, Liu CL, Zhou H, Zou ZS. A mathematical model considering the interaction of bubbles in continuous casting mold of steel. Powder Technol., 2015, 273, 154.

[6] Wang YF, Zhang LF. Transient fluid flow phenomena during continuous casting: Part 1—cast start. ISIJ Int., 2010, 50(12): 1777.

[7] Wang YF, Zhang LF. Transient fluid flow phenomena during continuous casting: Part 2—cast speed change, temperature fluctuation, and steel grade mixing. ISIJ Int., 2010, 50(12): 1783.

[8] Li XL, Li BL, Liu ZQ, Niu R, Liu YQ, Zhao CL, Huang CD, Qiao HS, Yuan TX. Large eddy simulation of multi-phase flow and slag entrapment in a continuous casting mold. Metals, 2018, 9(1): 7.

[9] Yang HJ, Vanka SP, Thomas BG. Mathematical modeling of multiphase flow in steel continuous casting. ISIJ Int., 2019, 59(6): 956.

[10] Fei P, Min Y, Liu CJ, Jiang MF. Effect of continuous casting speed on mold surface flow and the related near-surface distribution of non-metallic inclusions. Int. J. Miner. Metall. Mater., 2019, 26(2): 186.

[11] Chen W, Ren Y, Zhang LF, Scheller PR. Numerical simulation of steel and argon gas two-phase flow in continuous casting using LES+VOF+DPM model. JOM, 2019, 71(3): 1158.

[12] Cho SM, Kim SH, Thomas BG. Transient fluid flow during steady continuous casting of steel slabs: part I. measurements and modeling of two-phase flow. ISIJ Int., 2014, 54(4): 845.

[13] Kubota J, Kubo N, Ishii T, Suzuki M, Aramaki N, Nishimachi R. Steel flow control in continuous slab caster mold by traveling magnetic field. NKK Tech. Rev., 2001, 85, 1.

[14] Cao N, Zhu MY. Conditions for formation of a double-recirculation flow pattern in a slab continuous casting mold with argon blowing. Acta Metall. Sin., 2008, 44(5): 626.

[15] Deng XX, Ji CX, Cui Y, Zhu GS, Li LP, Suo QL. Flow pattern in continuous casting slab mold with argon blowing. Iron Steel, 2016, 51(10): 23.

[16] Chen W, Ren Y, Zhang LF. Large eddy simulation on the two-phase flow in a water model of continuous casting strand with gas injection. Steel Res. Int., 2018, 90(4): 33.

[17] Bai H, Thomas BG. Effects of clogging, argon injection, and continuous casting conditions on flow and air aspiration in submerged entry nozzles. Metall. Mater. Trans. B, 2001, 32(4): 707.

[18] Asad A, Kratzsch C, Schwarze R. Numerical investigation of the free surface in a model mold. Steel Res. Int., 2016, 87(2): 181.

[19] Hagemann R, Schwarze R, Heller HP, Scheller PR. Model investigations on the stability of the steel-slag interface in continuous-casting process. Metall. Mater. Trans. B, 2013, 44(1): 80.

[20] Bai H, Thomas BG. Turbulent flow of liquid steel and argon bubbles in slide-gate tundish nozzles: Part II. Effect of operation conditions and nozzle design. Metall. Mater. Trans. B, 2001, 32(2): 269.

[21] Deng XX, Huang Q, Wang XH, Li LP, Ji CX, Zhu GS. Effect of solidified shell on level characteristics in continuous casting slab molds for high speed casting. J. Univ. Sci. Technol. Beijing, 2014, 36(9): 1247.

[22] Yu HX, Deng XX, Wang XH, Ji CX, Zhu GS. Characteristics of subsurface inclusions in deep-drawing steel slabs at high casting speed. Metall. Res. Technol., 2015, 112(6): 608.

[23] Deng XX, Xiong X, Wang XH, Li LP, Hao CH, Wei PY, Ji CX. Effect of nozzle bottom shapes on level fluctuation and meniscus velocity in high-speed continuous casting molds. J. Univ. Sci. Technol. Beijing, 2014, 36(4): 515.

[24] Miki Y, Takeuchi S. Internal defects of continuous casting slabs caused by asymmetric unbalanced steel flow in mold. ISIJ Int., 2003, 43(10): 1548.

[25] Liu R, Thomas BG, Sengupta J, Chung SD, Trinh M. Measurements of molten steel surface velocity and effect of stopper-rod movement on transient multiphase fluid flow in continuous casting. ISIJ Int., 2014, 54(10): 2314.

[26] Zhang T, Yang J, Jiang P. Measurement of molten steel velocity near the surface and modeling for transient fluid flow in the continuous casting mold. Metals, 2019, 9(1): 36.

[27] Zhang T, Luo ZG, Zhou H, Ni B, Zou ZS. Analysis of two-phase flow and bubbles behavior in a continuous casting mold using a mathematical model considering the interaction of bubbles. ISIJ Int., 2016, 56(1): 116.

[28] Deng XX, Ji CX, Cui Y, Li L, Yin X, Yang Y, Mclean A. Flow pattern control in continuous slab casting moulds: Physical modelling and plant trials. Ironmaking Steelmaking, 2017, 44(6): 461.

[29] Kunsteich S, Dauby PH. Effect of liquid steel flow pattern on slab quality and the need for dynamic electromagnetic control in the mould. Ironmaking Steelmaking, 2005, 32(1): 80.