STUDY ON CORROSION BEHAVIOR OF Q235 STEEL AND 16MN STEEL BY ELECTROCHEMICAL AND WEIGHT LOSS METHOD

This study investigates the corrosion characteristics of Q235 steel and 16Mn steel in the sulfur-containing alkaline solution. The composition and the morphology of the corrosion products were analyzed by XPS and SEM respectively. The electrochemical behavior of Q235 steel and 16Mn steel was evaluated by potentiodynamic polarization curve and EIS. The results indicated that the corrosion rate of Q235 steel is greater than 16Mn steel in the early corrosion. Pitting and selective corrosion appeared on the surface of the two steels, and the surface product layer was granular and defective. XPS and EDS indicate that the structurally stable iron oxide is formed on the surface of the two steels. Electrochemical results show the corrosion kinetics of Q235 steel and 16Mn steel are simultaneously controlled by the charge transfer and ion diffusion, and the formation mechanism of corrosion products was clarified.