Atomic-Scale Corrosion Mechanism of Steel in NaCl Aqueous Solution: Effects of Temperature and Dissolved Oxygen

The corrosion of steel in chloride-containing aqueous environments can lead to progressive surface damage and structural degradation, posing a serious threat to the service reliability of marine and related engineering structures. In this study, reactive molecular dynamics simulations were employed to investigate the atomic-scale corrosion behavior of Fe-C steel in NaCl aqueous solution under different temperatures and dissolved oxygen contents. During the corrosion process, H2O, O2, and Cl− migrate to the steel surface, accompanied by H2O dissociation, Fe-O/Fe-Cl bond formation, and Fe dissolution, while corrosion-induced von Mises stress and volumetric strain are mainly distributed in the oxide layer; increasing temperature promotes Fe dissolution, oxide layer thickening, and local deformation, whereas higher dissolved oxygen content enhances Fe-O reactions and oxide growth. Overall, temperature primarily enhances corrosion by accelerating atomic transport and interfacial reaction kinetics, whereas dissolved oxygen affects corrosion through its combined influence on interfacial oxidation, Cl−-mediated reactions, and the evolution of the corrosion product layer, providing an atomic-scale insight into steel corrosion in Cl−-containing aqueous environments.