Short-Term Corrosion Characteristic of Q235 Steel under Different Atmospheric Environments of Hunan

In this paper, atmospheric corrosion behavior of Q235 steel in Hunan was studied using SEM/EDS, XRD and electrochemical measurement. The results showed that the corrosion products of the steel after one-year exposure in Hunan were mainly composed of alpha-FeOOH, gamma-FeOOH, Fe3O4 and Fe2O3. At the five selective sites, the minimum and maximum corrosion rates of the steel exhibited in the Gaoyun (rural) and Mengdu (mining area) sites, respectively. The increasing order of the pit depth of the steel was as this sequence: Gaoyun, Jiuhua (urban), Shanjuan (urban industry), Mingshan (fresh water lake area) and Mengdu. The pit depth of the skyward surface was generally 10-20 mu m deeper than that of the earthward surface in the same sites. The pollutants and relative humidity were the important factors affecting the atmospheric corrosion behavior of the steel.