Effect of Corrosion Products on Corrosion Process of 6061 Aluminium Alloy in Marine Atmosphere

6061 aluminium alloy was corroded in salt-spray as a simulated marine atmospheric environment to study the effect of corrosion products on the corrosion process of 6061 aluminium alloy. The electrochemical characteristics and corrosion morphology of 6061 aluminium alloy covered by corrosion products were analyzed by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and optical profilometry (OP). The results show that the corrosion product layer on the surface of 6061 aluminium alloy had a protective effect on the substrate, but the protective effect became weak with the increase of corrosion time. Pitting was the main form in the corrosion process of 6061 aluminium alloy. Corrosion products acted as a barrier to prevent the growth of pits, and promoted the transformation from pitting corrosion into uniform corrosion in the later stage of pitting corrosion.