Characterization and Corrosion Behavior of High-Nitrogen HP-13Cr Stainless Steel in CO2 and H2S Environment

The effect of nitriding on the corrosive properties of HP-13Cr stainless steel in extremely aggressive environmental conditions was investigated. The composition, structure, and corrosion resistance of HP-13Cr before and after adding nitrogen were investigated with X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), atom probe tomography (APT), and electrochemical autoclave. The results show that nitrogen is probably enriched at the grain boundary during diffusion, strengthening the grain boundary. This plays a decisive role in the improvement of corrosion resistance. After nitriding, the corrosion resistance of HP-13Cr stainless steel in both CO2 and CO2/H2S environments was significantly improved. This study provides a reference for this method to improve the corrosion resistance of stainless steel in extreme aggressive environments.