Effect of Argon Blowing Rate on Multiphase Flow and Initial Solidification in a Slab Mold

Abstract

The multiphase flow, heat transfer, and initial solidification behaviors in a 230 × 1300 mm2 continuous casting slab mold under different argon blowing rates were investigated by a multi-physical model. Water model experiments were conducted to validate the numerical models. The results showed that the simulated steel/slag level fluctuation and argon bubble trajectories were basically consistent with the experimental results. Only the bubbles less than 1 mm were dragged to the narrow face, while larger bubbles were more likely to escape from the free surface. When the argon blowing rate increased from 0 to 15 L/min, the impact depth of the molten steel decreased. The velocity and level fluctuation range near the submerged entry nozzle (SEN) first decreased and then increased. Moreover, the largest level fluctuation decreased to 4 mm when the argon blowing rate was 5 L/min. Meanwhile, the solidified shell thickness at narrow face of mold outlet decreased from 12.5 to 6.7 mm and became too thin to easily break out when argon blowing rate reached over 10 L/min. By comprehensively considering the multiphase flow, heat transfer, and solidification behavior in the mold, the proper argon blowing rate range should be 5 L/min, by which the disqualification rate of inclusion at strip edge can be decreased from 4.28 to 1.75 pct.