Short Communication Corrosion Behavior of D32 Rust Steel in Seawater

Rust layers were formed on D32 steel in seawater for 30 days, 90 days and 180 days respectively, and the micrographs and element compositions of the rust were investigated using SEM and XRD. The electrochemical corrosion behavior of the D32 steel with rust layer was investigated with polarization curves and electrochemical impedance spectroscopy. The inner rust layer was bent flaky and composed of Fe3C mainly. The outer layer was large flaky with cracks and composed of γ-FeOOH mainly. With the metal dissolution, Fe3C left on the metal forming the inner rust layer. With the presence of Fe3C, the rust was unable to form a protective layer, resulting in the increased corrosion rate in half a year