The effect of calcination on the corrosion performance of TiO2 sol–gel coatings doped with benzotriazole on steel CK45

Sol–gel method under dip coating process and tetra‐n‐butyle orthotitanate as precursor were used to produce titanium oxide coating on steel CK45. The effect of calcination at 400 °C, after drying at 120 °C, on the morphology and corrosion performance of the coatings was investigated. Benzotriazole (BTA) as an inhibitor was doped on titanium oxide coatings to improve corrosion performance of the coatings as well as its self‐healing properties. The morphology and structure of the coatings were studied by X‐ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X‐ray spectroscopy (EDS) techniques. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used to study the corrosion behavior of the coatings. The results revealed that after calcination the dominant crystalline phase was anatase. The results obtained from potentiodynamic polarization curves and electrochemical impedance spectra showed that the calcinated and doped with BTA coatings possessed higher corrosion resistance than non‐calcinated although doped with BTA coatings.