Corrosion resistance behavior of weathering GR65 steel under marine and industrial atmospheric environment

Abstract

This paper focused on the corrosion resistance of weathering GR65 steel under marine and industrial atmospheric environments, the weight loss method and Tafel method were respectively used to judge the anticorrosion mechanism. The corrosion resistance of Q345 steel, which has been commonly used in transmission towers and steel factory buildings, was also investigated for comparison. The 3.5%NaCl solution and 3.5%Na2SO4 solution were respectively adopted to simulate the marine and industrial atmospheric environment, and the corrosion resistance of GR65 and Q345 steel in these two types of solution were carefully discussed and compared. The results show that GR65 and Q345 are more prone to corrosion in 3.5%NaCl solution than in 3.5%Na2SO4 solution, Specifically, the corrosion rate of GR65 is about 51% and 52.7% lower than that of Q345 respectively in 3.5%NaCl and 3.5%Na2SO4 solution. The rust layer on the surface of Q345 steel is poor in continuity, loose-porous, and easy to peel, which fails to prevent the rust layer from continuing to develop inward. Comparatively, the rust layer of GR65 surface exhibits good density, continuity, and strong adhesion, which is helpful in slowing down the further development of the rust. Thus, the GR65 shows better corrosion resistance than Q345 steel.