Study on corrosion performance and corrosion product composition of weathering steel and high-performance steel in simulated C3 environment

Weathering steel (WS) and high-performance steel (HPS) have been widely used in bridge engineering. Investigating the corrosion performances of WS and HPS is of great significance to the safety evaluation and maintenance of uncoated WS or HPS bridges, especially aging bridges. This study focused on the correlation between the corrosion performance and composition of the rust layer. Accelerated corrosion tests were conducted on Q345CNH and HPS 70 W to observe their corrosion performance under salt-spray corrosive environment. Based on the results of corrosion test and the existing corrosion attack evaluation theories, the empirical formulae of uniform corrosion and pitting corrosion were derived. X-ray diffraction experiments were performed to analyze the composition of the rust layer formed on the surface of steel specimens after various corrosion cycles. The relationship between the composition of the rust layer and the corrosion performance was established. The test corrosive environment was verified to be consistent with the C3 environment. The conclusions of this study could provide guidance for the corrosion evaluation in the following test or practical application.