Corrosion Behaviors of S355 Steel under Simulated Tropical Marine Atmosphere Conditions

Salinity, temperature, humidity and illumination are main factors in determining the corrosion tendency of metallic materials under tropical marine atmosphere environment. In this paper, the weight loss, corrosion products, corrosion morphologies and electrochemical properties of S355 steel under simulated tropical marine atmosphere conditions were investigated. Different corrosion rules can be concluded under different atmospheric corrosion factors. The corrosion rate reaches maximum when the salinity content is 1.75%. S355 steel is easy to be corroded between 30 and 35 °C. The critical humidity of the S355 steel corrosion is 75%. The moisture condensing and illumination realizes dynamic balance at 70 W/m2, suggesting a lowest corrosion rate. In addition, the corrosion morphologies caused by salinity and illumination reveal uniform corrosion, while the corrosion morphologies caused by humidity and temperature show localized pitting corrosion. We believe the findings of this research will support the understanding of tropical marine atmospheric corrosion of metallic materials.