Corrosion Mechanism and Simulation of Q235 Steel in Typical Marine Atmospheric Environment

ABSTRACT This paper studies Q235 steel corrosion behavior and mechanism in the typical marine environment, a corrosion model of Q235 steel with a defective passivation film in a marine atmospheric environment is developed based on the electrochemical corrosion module in the COMSOL software, and the whole corrosion process is simulated by means of finite element analysis. The results show that the corrosion of Q235 steel in the marine atmospheric environment starts at the passive film defect, and over time, it gradually develops from pitting corrosion to intergranular corrosion, and then gradually develops from intergranular corrosion to comprehensive corrosion. The whole corrosion process is from point to surface. In addition, a rapid assessment model of the corrosion life of Q235 steel was established by cyclic salt spray accelerated corrosion test. It is verified that the kinetics of the corrosion weight loss of the Q235 steel is in accordance with the power function law, and also observed that Q235 steel surface passivation film as well as passivation film rupture after the generation of dense α‐FeOOH rust layer all play a role in resisting corrosion.