Studies on Hybrid Sol–Gel Silica/PVP Coatings on Modified 9Cr–1Mo Steel

Modified 9Cr–1Mo (mod.9Cr–1Mo) steel specimens were coated with polyvinylpyrrolidone based hybrid sol–gel coating doped with the corrosion inhibitor, 2-mercaptobenzothiazole. These coatings were characterized using atomic force microscopy and Raman spectroscopy. The corrosion resistance of surface mod.9Cr–1Mo steel in NaCl medium was evaluated using AC impedance studies. It was possible that the polymer based sol–gel coating prevented the aggressiveness of chloride attack by forming a complex with the inhibitor molecules and delayed the corrosion process on mod.9Cr–1Mo surfaces.