An electrochemical and analytical assessment on the early corrosion behaviour of galvanised steel pretreated with aminosilanes

This work investigates a pretreatment for coil-coated galvanised steel based on the use of gamma-aminopropyltriethoxysilane (γ-APS). The work aims at understanding the early corrosion-induced deterioration of the silane film. The electrochemical behaviour of the pretreated substrate was assessed by electrochemical impedance spectroscopy and potentiodynamic polarisation. The analytical characterisation was performed by X-ray photoelectron spectroscopy (XPS) analysis and scanning electron microscopy (SEM). The results show that the pretreatment provides temporary corrosion protection of the substrate. Simultaneously, the work discusses the early deterioration of the silane film.