In Situ Growth of NiFe Layered Double Hydroxide Coating for the Corrosion Inhibition of 316 and 304 Stainless Steels in 3.5 wt.% NaCl Solution

Layered double hydroxide has been recognized as a promising material to prevent metals and its alloy from corrosion owing to their unique structure, composition, anion exchange and other excellent properties. This study aims to improve the corrosion resistance of stainless steel using an LDH coating in a corrosive media. NiFe LDH was synthesized via coprecipitation method at constant pH; then the prepared material was used for the corrosion inhibition of 316 and 304 stainless steels in NaCl solution. In situ growth of NiFe LDH film on the substrate surface was done via a hydrothermal method. The surface morphology, structure and composition of the LDH coating were characterized by scanning electron microscopy and x-ray diffraction. The corresponding corrosion inhibition properties were investigated by electrochemical methods, including electrochemical impedance spectroscopy and Tafel curves. A remarkable improvement in the corrosion inhibition of 316 and 304 SS was observed after LDH coating growth; this was confirmed by a significant increase in the polarization resistance and a decrease in the corrosion current density, which also indicates the successful in situ growth of the LDH on the substrate. The results revealed that the coating effectively inhibits corrosion in corrosive media for 316 and 304 SS.