Study on Multiphase Flow and Homogenization Behavior During Rare Earth Alloying of Molten Steel

doi:10.12068/j.issn.1005-3026.2025.20240046

Abstract

Abstract:

In order to study the behavior during the mass transfer and homogenization in the molten pool by argon blowing at the bottom of the ladle in the refining process， a LES-DPM-VOF coupled numerical model for a 150 t ladle in a steel plant was established to simulate slag-steel-argon three phase flow， and the effects of argon blowing rates on multiphase flow behavior of slag-steel-argon and the homogenization phenomenon of liquid steel were studied. The results show that the shape of the slag hole predicted by the numerical model is in good agreement with experimental observations. When the blowing rate is 50 L/min， the maximum velocity of molten steel in the ladle is about 0.7 m/s， and the slag-steel interface only shows a little fluctuation without the formation of a slag hole. As the blowing rate increases from 50 L/min to 100 L/min， the lifting effect of bubbles on molten steel is enhanced， and the maximum upward velocity of molten steel increases from 0.7 m/s to 1.07 m/s. In addition， the fluctuation of the slag-steel interface increases. Furthermore， the study on homogenization behavior shows that the homogenization time of the alloy is inversely proportional to the argon blowing rate. When the diameter of the simulated alloy is 20 cm and the blowing rate is 50 L/min， the homogenization time is 245 s. When the blowing rate increases to 300 L/min， the homogenization time decreases to 145 s.

Key words: steel ladle refining, alloying, multiphase flow, homogenization time, numerical simulation

CLC Number:

TF 769

Yun-long HAO, Qing-hua XIE, Pei-yuan NI, Ying LI. Study on Multiphase Flow and Homogenization Behavior During Rare Earth Alloying of Molten Steel[J]. Journal of Northeastern University(Natural Science), 2025, 46(9): 73-80.

Figures/Tables 14

Fig.1 Geometry model of ladle and bottom blow nozzle diagram

Table 1 Physical parameters and process conditions

参数	值
钢液密度/(kg·m^-3)	7 020
La-Fe液态合金密度/(kg·m^-3)	6 600
La-Fe合金比热容/(J·(kg·K)^-1)	535.32
钢液黏度/(kg·m^-1·s^-1)	0.005 5
渣的密度/(kg·m^-3)	3 500
渣的黏度/(kg·m^-1·s^-1)	0.06
渣相顶部空气密度/(kg·m^-3)	0.5
渣相顶部空气黏度/(kg·m^-1·s^-1)	0.000 089
氩气密度/(kg·m^-3)	1.623
吹气量/(L·min^-1)	50，100，300
渣-钢水界面张力/(N·m^-1)	1.15
渣-空气界面张力/(N·m^-1)	0.58
钢水-空气界面张力/(N·m^-1)	1.82
La-Fe合金中La质量分数/%	0.5

Fig.2 Comparison between size of slag holes in water model and results of numerical simulation

Fig.3 Velocity distribution under different grid numbers

Fig.4 Bubble distribution in molten steel with different argon blowing time

Fig.5 Molten steel velocity distribution

Fig.6 Slag-metal interface behavior at different argon blowing rates

Fig.7 Distribution of slag holes at different injection time

Fig.8 Slag distribution at different time

Fig.9 Simulation of temperature change during melting process of alloys in molten steel

Fig.10 Diagram of dynamic process of alloy melting and diffusion

Fig.11 Homogenization time of flow field

Fig.12 Homogenization time at different injection flow rates

Fig.13 Homogenization time of alloys with different densities at 100 L/min flow rate

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