Effect of the Rare Earth Element Cerium on the Corrosion Resistance of Steel for an Offshore Platform in a Simulated Marine Atmospheric Environment

This study investigated the corrosion behavior and mechanism of offshore platform steel in a simulated marine atmospheric environment using electrochemical analysis, phase analysis, and rust layer characterization. The findings demonstrate that the addition of trace amounts of the rare earth element Ce significantly enhances the steel's corrosion resistance in the marine environment and effectively reduces the corrosion rate. The addition of Ce promotes the enrichment of Cr in the inner rust layer and forms a dense protective rust layer, thereby preventing the rust layer from falling off, as well as hindering the penetration of oxygen ions. Phase analysis and electrochemical studies further confirmed that the addition of rare earth Ce optimized the structure of the rust layer, improved the matrix protection effect, and enhanced the corrosion resistance of the steel. The crystal structure of the rust layer and the stability between the matrix were simulated by first principles. The results show that the addition of rare earth enhances the bonding force and compactness of the steel matrix and the rust layer, thereby improving corrosion resistance.