The Beneficial Role of Sn in Rapid Rust Stabilization of Weathering Steel in Marine Environments

Weathering steel has excellent corrosion resistance and is widely used in bridges, towers, railways, highways and other engineering that are exposed to the atmosphere for long periods of time. However, before forming stable rust layer, weathering steel is prone to issues such as rust liquid sagging and spattering, leading to environmental pollution and city appearance concerns. These factors limit the application and development of weathering steel. In this study, we developed a rapid and environmentally friendly method by introducing alloying elements, specifically investigating the role of tin (Sn) in the rapid stabilization of the rust layer in a marine atmospheric environment. In this work, we explored the rust layer formed on weathering low-alloy steel exposed to prolonged outdoor conditions and laboratory immersion experiments by EPMA, micro-Raman, XPS and electrochemical measurements. The results showed an optimal synergistic effect between Sn and Cr, which facilitated the accelerated densification of the rust layer. This beneficial effect contributed to enhancing the ability of the rust layer to resist Cl- erosion and improving the protection performance of the rust layer.