Corrosion and pitting of 6060 series aluminium after 2 years exposure in seawater splash, tidal and immersion zones

Highlights: • Presents new observations for localized marine corrosion and pitting of aluminium exposed for 2 years. • Pitting and localized corrosion was more severe in the immersion zone compared with the tidal and splash zones. • Corrosion morphologies observed include deep pitting and intergranular and crystallographic attack. • Complex morphologies were observed for the deepest pits. - Abstract: New longer-term observations of corrosion and pitting of 6060-grade aluminium alloy showed that the most intensive pitting and corrosion occurred in the marine immersion zone. After 2 years exposure the corrosion morphology included shallow and deep pits, intergranular corrosion and crystallographic attack. The deepest pits showed complex morphologies, spatially and with depth. This is considered the result of localized anoxic conditions formed under accumulated corrosion products. Less severe corrosion was observed in the splash and tidal zones. For these the pit morphologies were less complex.