Study of the deoxidation of steel with aluminum wire injection in a gas-stirred ladle

In the present work, the deoxidation of liquid steel with aluminum wire injection in a gas-stirred ladle was studied by mathematical modeling using a computational fluid dynamics (CFD) approach. This was complemented by an industrial trial study conducted at Uddeholm Tooling AB (Hagfors, Sweden). The results of the industrial trials were found to be in accordance with the results of the model calculation. In order to study the aspect of nucleation of alumina, emphasis was given to the initial period of deoxidation, when aluminum wire was injected into the bath. The concentration distributions of aluminum and oxygen were calculated both by considering and not considering the chemical reaction. Both calculations revealed that the driving force for the nucleation fo Al₂O₃ was very high in the region near the upper surface of the bath and close to the wire injection. The estimated nucleation rate in the vicinity of the aluminum wire injection point was much higher than the recommended value for spontaneously homogeneous nucleation, 10³ nuclei/(cm³/s). The results of the model calculation also showed that the alumina nuclei generated at the vicinity of the wire injection point are transported to other regions by the flow.