Corrosion Process and Rust Formation of Weathering Steel

By observing the initial corrosion process of weathering steel under thin liquid film and analyzing the rust layers of the experimental steels, the formation mechanism of protective rust layer was discussed. The results show that the corrosion processes were different between weathering steel and carbon steel in the initial corrosion process, the corrosion of weathering steel was uniform corrosion and pitting corrosion, and the corrosion of carbon steel was non-uniform corrosion. The micrographs of the rust layers of the two steels were also different in the later corrosion stage, the rust layer of weathering steel was non-uniform because of many corrosion pits and the rust layer of carbon steel uniform but with many cracks.