Abstract: A water/carbon dioxide system was used to study bubble growth dynamics in a molten steel/(N₂,H₂) supersaturation system. Bubble nucleation and growth mechanism models in the aqueous solution and the molten steel were respectively established.Bubble growth dynamics in the water/carbon dioxide system and the molten steel/(N₂,H₂) system was studied based on three different kinds of bubble growth mathematical models. Water modeling experimental data were used to validate the mathematical models. The influences of preprocessing pressure,post-processing pressure and the depth of molten steel on bubble growth were analyzed in the molten steel/(N₂,H₂) system. It is found that when using the technology of inclusion removal by bubble flotation,preprocessing pressure has significant effect on the bubble growth. However,post-processing pressure blocks the bubble growth,and with increasing post-processing pressure,the influence gradually strengthens. The depth of molten steel has retarding effect on the bubble growth,and with the increasing of the depth of molten steel,the influence gradually weakens. Compared with nitrogen bubbles,hydrogen bubbles in molten steel grow faster.