Optimization of Mo on the corrosion resistance of Cr-advanced weathering steel designed for tropical marine atmosphere

The effect of Mo on the corrosion resistance of Cr-advanced weathering steel designed for the tropical marine atmosphere was studied through the morphology characteristics, element distribution, phase composition and electrochemical characteristics of the corrosion products. The results indicated that Mo mainly forms nano-sized MoO2 and MoO3, which destroy the network structure of Fe(O, OH)(6), and provide more nucleation sites for newly formed corrosion products, thereby promoting the conversion of gamma-FeOOH to alpha-FeOOH. Mo also promotes the conversion of CrO3 in the corrosion products to more stable and corrosion resistant Cr2O3 and Fe2CrO4. In addition, Mo promotes the enrichment of Cu in the form of Cu and Cu2O at the interface between the corrosion product layer and the substrate. The comprehensive effect of Mo makes the corrosion product layer show more excellent stability and compactness, effectively inhibit the invasion of Cl-, so the corrosion resistance of 0.1Mo steel is improved.