Niobium and carbon nanostructured coatings for corrosion protection of the 316L stainless steel

Abstract

This work aims to investigate the influence of niobium and carbon nanostructured coatings on the corrosion resistance of the 316L SS. The coated and uncoated specimens were morphologically and structurally characterized by using OM, SEM/EDX, DRX, FTIR, Raman spectroscopy and XPS techniques. The corrosion behaviour was assessed by OCP, PPc, EIS as well as immersion tests in 0.6 mol L−1 NaCl solution. In addition, the average contact angles were used to evaluate the surfaces free energy by the Van Oss interfacial tension component theory approach. Results showed that the surface treatments positively influenced the corrosion resistance of the 316L SS and the coatings act as a protective barrier against corrosion process. The reactive sputtering technique increased the wettability of the surfaces in relation to the base material. Considering applications in aggressive media, the 316L SS/Nb2O5 specimen exhibits superior performance when compared to the base material and 316L SS/carbon.