Analysis on Localized Corrosion Causes of Galvanized Al-Mg Steel Plate Coated with Chromium Free Passivator and Antirust Oil

In order to explore the corrosion mechanism of galvanized Al-Mg steel plate coated with chromium-free passive solution and anti-rust oil in the transportation environment，XPS and EDS were used to analyze the element differences in the color-difference zone.The microstructure of chromium-free passive film of the galvanized sheet before and after corrosion was investigated by atomic force microscope.Raman spectroscopy was used to analyze the curing mechanism and protection process of coated chromium-free passivator.Results showed that the reaction between the components of antirust oil and passive film affected the antirust performance of the coating film.Raman spectrum revealed that the cured plate could be cured more completely by increasing the temperature to 90 ℃，and the anti-rust ability was obviously enhanced.