The role of post-treatment of an ecofriendly cerium nanostructure Conversion coating by green corrosion inhibitor on the adhesion and corrosion protection properties of the epoxy coating

•The cerium nanostructure coating was modified by a post-treatment bath of Urtica extract.•Post-treatment of the cerium coating with inhibitor led to the film with highest compactness.•Post-treatment of the cerium coating with inhibitor significantly reduced the delamination rate of epoxy coating.•The corrosion protection performance of the epoxy coating remarkably increased on the cerium coating after post-treatment.

This study introduces a green strategy for enhancement of the corrosion protection and adhesion properties of an epoxy coating applied on the steel surface treated by cerium conversion coating (CeCC) and then post-treated by Urtica inhibitor. The corrosion behavior of the coatings was evaluated by electrochemical impedance spectroscopy and salt spray test. Scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy and contact angle measurements were adopted for surface characterization. For further investigations, pull-off and cathodic disbondment tests were performed. Results demonstrate the beneficial role of the post-treatment of CeCC by Urtica inhibitor on the enhancement of the epoxy coating performance.

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