Insight into Intergranular Corrosion of the Aluminum Alloy 2024-T3: Effect of Pre-Charged Hydrogen

Abstract

2024-T3 aluminum alloy has been widely applied in aviation fields, but the accumulation of hydrogen at grain boundaries deteriorates the mechanical properties and corrosion resistance. The intergranular corrosion of 2024-T3 related to hydrogen permeation was investigated. Atom probe tomography was used to observe the precise position of hydrogen atoms in relation to grain boundaries. The ionic current density of the H pre-charged surface was studied by in-situ scanning vibrating electrode technique. Results show that the distribution of H is highly related to the S-phase at grain boundaries and the H pre-charging significantly improves the charge transfer efficiency at the initial period of intergranular corrosion process while the enhancement effect is then gradually weakened. The study provides new insight into hydrogen distribution at grain boundaries and its impact on the intergranular corrosion of 2024-T3 aluminum alloy, which can be informative and instructive for the research of corrosion in aluminum alloy.