Synergistic Effect of Different NaCl Concentrations on the Initial Corrosion of Q235 Steel under a Simulated SO 2 Environment

Abstract The synergistic effect of chloride ions and industrial corrosive gases in the atmosphere intensifies metal corrosion. Therefore, the study of this corrosive behavior and its effects on metals in complex environments is crucial. In this study, the wet/dry cyclic corrosion test, under a constant deposited salt, was used to simulate atmospheric corrosion conditions. In addition, the methods of corrosion weight gain, dynamic potential polarization curves, electrochemical impedance spectroscopy, and other analyses were used to explore the mechanism and law of Q235 steel with different corrosion times in different coastal‐industrial atmospheric environments. The corrosion pattern of Q235 steel and the composition of the rust layer were further investigated through X‐Ray Diffractometer analysis and Scanning Electron Microscope observations. The results show that the content of Fe 3 O 4 decreases at higher chloride ion concentrations and the content of α‐FeOOH increases in later stages of corrosion.