Self‐Repairing of Damaged Rust Layers on Carbon Steel and Weathering Steel

Rust layer damage of the weathering steel is almost inevitable during its service and new rusts will form to fill the damage. This study focused on the rust self-repairing behavior of the weathering steel in the corrosion process, which was compared with that of the carbon steel. The results indicated that: the alloy elements in the weathering steel improve the compactness of the new rust layer, so that the steel surface is quickly covered with new rust layer. Since there is no alloy element in the carbon steel, the rust layer is loose though it is thicker than that on the weathering steel. As the self-repairing rust layers grow thicker, the stress between the new and the original rust layers occurs. In order to release the stress, cracks produced in junction between the newly formed rust layer and the original rust layer.