ANALYSIS OF THE CORROSION RUST ON WEATHERING STEEL AND CARBON STEEL EXPOSED IN MARINE ATMOSPHERE FOR THREE YEARS

Corrosion of carbon steel and weathering steel exposed for 3 years in Hainan and in Qingdao was compared. The rust layers formed on the weathering steel exposed to marine environments for 3 yeas have been characterized by means of IR absorption technique. The distribution of deferent components and alloy elements in the rust layer was determined. The inner rust layer formed on the weathering steel is mainly α FeOOH while the outer rust layers formed on weathering steel and whole rust layers formed on the carbon steel are α FeOOH,γ FeOOH,Fe 3O 4. Cr element is found in the inner rust layers formed on the weathering steel, and S, Cl elements are found in the outer rust layers and whole rust layers formed on the carbon steel. The functions of Cr , Cl and S in the rust layers have been analyzed.