THE PROGRESS OF INVESTIGATION ON WEATHERING STEEL AND ITS RUST LAYER

The development and the applying situation of weathering steel and progress in research on weathering steel were reviewed.Effect of alloy element such as Cu,P,Cr,Ni on the corrosion resistance of weathering steel and its mechanisms were summarized.At the same time,the research into the constitution of rust layer,the process and its transformation and revolution mechanisms,the development prospects of weathering steel were described.It was believed that the excellent corrosion resistance of weathering steels came from the addition of alloy elenments which make it form a dense and stable rust layer.The rust layer on weathering steel plays an important role on corrosion progress and prevention of the substrate steels.The composition and structure of rust layer varied with the additional elements and environment.The formation of rust layer in the wet-dry cycle condition is a complicate electrochemical process which contains different reaction of cathode and anode.