On the role of hydrogen during the corrosion processes affecting the 2024 aluminum alloy

Abstract

The aim of this study was to characterize the role of hydrogen on corrosion damage of AA 2024 induced by cyclic exposure to chloride media with air emersion periods at negative temperatures. Mechanical tests on both corroded and cathodically hydrogen-charged samples were conducted, combined with different observations and analyses, such as SIMS mapping and SEM observations. Concerning the corroded samples, due to the volume expansion of the electrolyte trapped inside the intergranular corrosion defects during emersion phases at -20 °C, different consecutive stress states appear during the corrosion tests close to corrosion defects and lead to the diffusion, transport and trapping of hydrogen produced during the corrosion reactions.