The failure behaviour of an epoxy glass flake coating/steel system under marine alternating hydrostatic pressure

Highlights: • The failure process of the epoxy coating is accelerated by alternating pressure. • The alternating pressure deteriorates the structure of the coating/steel system. • A failure mechanism of the coating/steel system is raised. - Abstract: The failure behaviour of an epoxy glass flake coating/steel system under marine alternating hydrostatic pressure (AHP) was studied by electrochemical impedance spectroscopy (EIS), gravimetric tests, adhesion tests and scanning electron microscopy (SEM). Results reveal that AHP promoted water transportation into the coatings, and deteriorated the interface structures of the coating/steel system, including the coating/steel interface and the pigment/binder interface in the coating body. The failure process of the coating/steel system under marine AHP is discussed in the paper