Study on corrosion mechanism of Al–Zn coatings in the simulated polluted marine atmosphere
Liyuan Xiao, Qianqian Liu, Jin Wang, Nana Chen, Junhang Chen, Jialiang Song, Xin Zhang, Kui Xiao
Abstract
The corrosion behavior of Al-Zn coatings on steel sheets in simulating polluted marine atmosphere was systematically evaluated by weight loss tests, potentiodynamic polarization curves, electrochemical impedance spectroscopy, and acid salt spray test. The results demonstrated that the AI-Zn coating produced a passivation film of Al2O3 with good corrosion resistance, forming a thick and dense layer of insoluble corrosion products. In addition, the corrosion products such as Zn5Cl2(OH)8• H2O and NaZn4(SO4)Cl(OH)6•6H2O hindered the diffusion of corrosive substances into the coating and thus inhibited further corrosion.
Topics & Concepts
CorrosionMaterials sciencePassivationDielectric spectroscopyCoatingMetallurgyPolarization (electrochemistry)ElectrochemistryDiffusionSalt (chemistry)Atmosphere (unit)Layer (electronics)Salt spray testChemical engineeringComposite materialElectrodeChemistryOrganic chemistryEngineeringPhysicsThermodynamicsPhysical chemistryCorrosion Behavior and InhibitionConcrete Corrosion and DurabilitySmart Materials for Construction