New coating stabilizing surface rust of weathering steel

A new coating, Zn-Ca phosphating/acrylic resin-SiO₂ (B-Si) composite films, was put forward, which can stabilize the surface rust of weathering steel. The wet and dry cycle immersion test was used to evaluate the corrosion resistance of this compound film. It was found that the optimum technology is Zn-Ca phosphating/B-13Si (120°C). It is efficient not only to avoid the liquid rust to flow and distribute but to promote the formation of stabilized rust layer. Furthermore, the mechanisms of the presented coatings to improve the corrosion-resisting property and to accelerate the formation of stabilized rust of weathering steel at atmosphere were also discussed.