Influence of macrofouling on the corrosion and hydrogen permeation behaviour of high-strength steel

This study elucidates the mechanisms by which macrofouling organisms influence the corrosion behaviour and hydrogen permeation of high-strength steels, employing field exposure experiments, electrochemical impedance spectroscopy, corrosion-product characterisation and microbial community analysis. The results show that dynamic biofouling shifts corrosion from uniform to localised, with pit morphology varying according to fouling type, while enriching the rust layer with conductive Fe 3 O 4 and anaerobic FeS. Fouling also promotes microbial diversification, markedly increasing the abundance of microbes within the inner rust regions. Hydrogen permeation is enhanced by microbial metabolism, corrosion-product hydrolysis, oxygen concentration cells and occlusive effects, thereby heightening the risk of hydrogen embrittlement. These findings provide a theoretical foundation for corrosion management and macrofouling protection in marine environments.