Effects of CO2 reaction-induced bubble proliferation on the dynamic conditions of stainless steel smelting molten pool

Abstract

In pursuit of advancing the utilization of CO2 in steel production processes, this study investigates the impact of CO2 reaction-induced bubble proliferation on the dynamic conditions of stainless steel smelting molten pool, focusing on the stirring dynamics and liquid steel flow. Combining numerical simulation and water experiments, the influence of volume increase on bubble expansion and splitting was quantitatively analyzed. Water experiments show a significant reduction in molten pool mixing times under bottom-blowing CO2 reactions, with reductions of 16.5 s and 8.4 s in bubble expansion and splitting scenarios compared to the control group. Numerical simulation reveals contrasting effects on the molten pool flow field, where bubble expansion enhances lateral solute diffusion, while splitting encourages longitudinal diffusion. Notably, the observed ink diffusion patterns in water experiments align seamlessly with the velocity distribution and flow patterns from numerical simulation, providing a qualitative validation. Analysis of “dead zones” within the molten pool demonstrates a decrease of 10.82 % and 9.25 % in the proportions of “dead zones” volume in bubble expansion and splitting groups, respectively. These findings emphasize the positive influence of CO2-induced bubble proliferation in minimizing low-velocity regions and enhancing overall uniformity in the molten pool. The study provides valuable insights for the iron and steel industry, supporting the transition towards sustainable practices and contributing to global initiatives for carbon neutrality.