Assessment of the anticorrosive efficiency of zinc phosphate (ZP) and epoxy resin (DGEBA-DAA) based composite (DGEBA-DAA-ZP) for electrolytic cadmium pre-treated 15CDV6 steel in 3wt% NaCl medium: experimental and computational studies

Abstract

The present study invokes on the assessment of the anticorrosive efficiency of zinc phosphate (ZP) and epoxy resin (DGEBA-DAA) based composite (DGEBA-DAA-ZP) for electrolytic cadmium pre-treated 15CDV6 steel in 3wt% NaCl medium. The composite formulation (DGEBA-DAA-ZP) performances as effective anti-corrosive coating at different exposure times ranging from 60, 120 and 180 days in a salt spray chamber. Electrochemical impedance spectroscopy (EIS) and molecular dynamic (MD) simulations were used to illustrate the anti-corrosive property of the composite. EIS study revealed that the composite acted as strong interface inhibitor and the anticorrosive behavior decreases with increasing the exposure time. Similarly, results reveal that the longer the exposure time, the lower the magnitude of charge transfer resistance (Rct) and coating resistance (Rpore). Results of MD simulation showed that the flat or nearly flat orientation of the DGEBA-DAA-ZP adsorbed on the Cd surface behaved as efficient anti-corrosive material.