Distribution Behaviors of Chromium and Sulfur Between Slag and Steel During Argon Oxygen Decarburization Refining Process

Based on the atomic–molecular coexistence theory (AMCT) in the metal and ion–molecule coexistence theory (IMCT) in the slag, a predictive model was developed to describe the distribution behavior of chromium and sulfur between slag and steel during the argon oxygen decarburization (AOD) refining process. The influence of steel composition ([Si], [Al]) and basicity ( R ₂ = w(CaO)/w(SiO ₂ )) on the distribution of chromium and sulfur was analyzed, with particular attention paid to the coupling effect between (Cr ₂ O ₃ ) reduction and desulfurization. The study found that increasing the contents of [Si] and [Al], as well as increasing basicity, can effectively promote the reduction of (Cr ₂ O ₃ ) and desulfurization. When [Si] = 0.25 wt%, [Al] = 0.004 wt%, [Cr] = 18 wt%, and R ₂  = 1.8, the final slag (Cr ₂ O ₃ ) content of 0.13 wt% and the sulfur distribution ratio ( L _S ) of 100 can be achieved. L _S shows a strong inverse relationship with the chromium distribution ratio ( L _Cr ); when L _Cr increases to 0.01, L _S decreases to approximately 100. To achieve deep desulfurization ( L _S  > 100), the (Cr ₂ O ₃ ) content must be strictly controlled to remain below 0.5 wt%. Finally, based on the model analysis, recommendations for optimizing process parameters during AOD refining of superaustenitic stainless steel 30432 were proposed to maintain a low sulfur content.