Mechanistic Modeling of Stress-Induced Electrochemical Heterogeneity and its Quantitative Impact on the Failure of Corroded Aluminum Alloy Plates

While the influence of stress on localized corrosion is recognized, the coupled mechanism underlying stress-induced electrochemical heterogeneity and the resulting load-bearing capacity degradation remains insufficiently quantified. This study proposes a coupled stress–electrochemical–geometrical evolution framework to evaluate corrosion evolution and residual load-bearing capacity of defective 6082-T6 aluminum alloy plates. In situ tensile electrochemical tests were conducted in the 3.5 wt% NaCl solution to identify stress-dependent electrode kinetic parameters, which were then incorporated into a secondary current distribution model coupled with elastoplastic analysis and moving-boundary corrosion evolution. The results show that the non-uniform stress field alters local electrode kinetics and creates spatial differences in anodic potential on the defect surface, thereby inducing stress-driven electrochemical heterogeneity. This heterogeneity promotes anodic current–density localization at the defect bottom and groove-intersection regions, leading to quasi-galvanic corrosion behavior and directional deepening of localized corrosion. Defect geometry significantly affects the stress-induced amplification of corrosion damage. The perpendicular elliptical defect represents the most critical configuration, with a corrosion-depth increase of 40.5 % under stress, exceeding those of the parallel elliptical defect (17.8 %) and circular defect (21 %). As the initial defect depth increases from 1 mm to 9 mm, the corrosion-depth increase rises from 5 % to 78.4 %. The proposed stress acceleration coefficient further shows that stress amplifies corrosion-induced load-bearing capacity loss by 10.49–34.8 %. This study provides a quantitative basis for assessing the failure risk of corroded aluminum alloy components under service loads.