Preparation and characterization of anticorrosive layers deposited by micro-arc oxidation on low carbon steel

Different types of composite layers containing aluminum oxide have been deposited by micro-arc anodic oxidation of carbon steel S235 JR, using an aqueous aluminate solution containing 7 g/l NaAlO2 and 2 g/l NaOH. yers were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), microanalysis and salt spray tests. tained layers contain aluminum oxideʹs polycrystalline phases (Al2O3-α and Al2O3-γ), are porous and have a thickness ranging from 3 to 11 μm. It also has been observed that increasing the layer thickness also increases the concentration of Al2O3-α polycrystalline phase and the occurrence time of red salt (rust). The anticorrosion properties of the deposited layers are limited because of their porosity.