Influence of hydrogen on the propagation of intergranular corrosion defects in 2024 aluminium alloy

Marie-Laëtitia De Bonfils-Lahovary (1) , Claudie Josse (2) , Lydia Laffont (1) , Christine Blanc (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 Centre Castaing - Centre de microcaractérisation Raimond Castaing

To study the influence of hydrogen on the intergranular corrosion mechanism of a 2024 aluminium alloy, samples were hydrogen precharged by cathodic polarisation and then exposed to a NaCl solution. EBSD analyses and SEM observations showed that hydrogen increased the number of corroded interfaces and led to the embrittlement of low-angle grain boundaries which were not susceptible to corrosion without hydrogen precharging. The increase of the reactivity of the 2024 aluminium alloy in the presence of hydrogen gave a new insight into the intergranular corrosion mechanism: corrosion-induced hydrogen promoted the intergranular corrosion propagation and partially controlled the corrosion defect morphology.

Mots clés: Aluminium; Hydrogen; EBSD; Intergranular corrosion; Interfaces

Domaines: Matériaux

Marie-Laëtitia De Bonfils-Lahovary, Claudie Josse, Lydia Laffont, Christine Blanc. Influence of hydrogen on the propagation of intergranular corrosion defects in 2024 aluminium alloy. Corrosion Science, 2019, 148, pp.198-205. ⟨10.1016/j.corsci.2018.12.019⟩. ⟨hal-02135687⟩