Synergy of Cu and Sb to enhance the resistance of 3%Ni weathering steel to marine atmospheric corrosion

Various contents of Cu and Sb elements were incorporated into 3%Ni steel to enhance its corrosion resistance in a simulated tropical marine atmosphere of high salinity. The electrochemical process and the corrosion product film (CPF) properties were analyzed to evaluate the role of Cu and Sb and their synergistic effect. The results showed that there was a synergy between 0.5 % Cu and 0.2 % Sb, which improved the corrosion resistance of 3%Ni steel. This synergy produced a 45-μm-thick inner layer enriched with Cu, Sb and Ni, optimizing the properties of CPF significantly in terms of compactness, phase composition, elemental distribution and electrochemical activity.