Machine learning-based prediction of alloying element effects on irradiation swelling in austenitic steels

摘要: Austenitic stainless steels have been extensively utilized as key structural components in nuclear reactors, yet they exhibit a strong tendency to undergo swelling under neutron irradiation, which consequently deteriorates their mechanical performance. Hence, reliable prediction of the swelling evolution in austenitic stainless steels is essential to guarantee their operational integrity during reactor service. This research draws on a curated dataset documenting neutron irradiation-induced swelling in austenitic stainless steels, in which correlation analysis and recursive feature elimination were used to identify critical factors governing swelling behavior—namely, temperature, neutron flux, and the concentrations of Cr, Mn, Ni, Si, P, and C. Based on the 15 selected features, a multilayer perceptron (MLP) model was developed for predictive analysis of swelling, enabling precise prediction of the peak swelling temperature and the dose corresponding to the swelling incubation stage. Using the trained MLP model, a quantitative relationship was established between the swelling rate and the elemental concentrations of Cr, Mn, Ni, Si, P, and C. The analysis revealed that higher Cr content consistently promotes swelling, while increases in Si and P (above 0.02 wt.%) effectively suppress swelling. Additionally, there exist threshold concentrations for Mn (2.5 wt.%), Ni (35 wt.%), and C (0.1 wt.%), beyond which swelling is most effectively mitigated. The results of elemental interaction analysis indicate that in austenitic stainless steels containing high levels of Cr, Ni must be increased to 15–20 wt.% to achieve enhanced swelling resistance. Under conditions of low C concentration, increasing the P content appropriately can enhance the material's resistance to irradiation-induced swelling. These findings offer quantitative guidance for designing and optimizing the composition of austenitic stainless steels with improved swelling resistance under irradiation.