Abstract: The corrosion behavior and corrosion-induced mechanical degradation of 2524-T3 aluminum alloy in pure chloride and HSO₃^--containing environments are investigated in the present work. The controlling factors and underlying mechanisms of the mechanical property degradation and the associated reversibility are discussed. In a pure chloride environment, the ductility loss is fully reversible, which is influenced by the corrosion product layer, the nature and depth of subsurface attack propagation, and the corrosion-induced hydrogen behavior. However, in the HSO₃^--containing environment, the ductility loss is predominantly irreversible, with a recovery rate of 14.6% after 48 h and only 3.4% after 72 h. This is attributed to changes in the initial pH, buffer effect, and the corrosion patterns, with the buffer effect accounting for 72% of the contribution to the irreversibility. The results provide insights to predict the reversibility of the mechanical property degradation in aluminum alloys, thereby addressing the challenges posed by corrosion in diverse environments for ensuring safe use and widespread application.

Key words: Aluminum alloy, Corrosion damage, Mechanical property degradation, Reversibility