Effect of rust layer stabilization on dry and wet cyclic corrosion behavior of bridge weathering steel Q345qNH in simulated industrial atmospheric medium

Abstract

It takes 3–5 years for the stable rust layer to form when the bridge weathering steel is used in the industrial atmosphere, and the loose rust layer appearing in the early stage will pollute the atmospheric environment. Therefore, a method for the rapid formation of stable rust layer is developed in this paper, and the influence of rust layer stabilizing treatment on corrosion behavior of bridge weathering steel Q345qNH in simulated industrial atmospheric medium is studied. The results showed that in simulated industrial atmospheric medium, the stabilizing treatment shortened the formation time of stable rust layer and significantly reduced the corrosion rate, which is 47.9 % lower than that of bare steel after 480 h of corrosion. During the whole corrosion process, the Iα-FeOOH/Iγ-FeOOH peak intensity ratio of the stabilizing treatment steel was always higher than that of the bare steel, and was 1.26 times that of the bare steel after 480 h corrosion. After the stabilizing treatment, the self-corrosion potential of the rust layer increases, the self-corrosion current density decreases, and the resistance of the rust layer after 480 h corrosion was 1.57 times that of the bare steel sample, and the protection of the rust layer was significantly improved.