Improving electrochemical corrosion resistance of AISI 304 using tungsten carbide-cobalt/silicon carbide high-velocity oxygen fuel coatings

Abstract

This study offers an in-depth analysis of the electrochemical corrosion behaviour of tungsten carbide-cobalt/silicon carbide coatings on AISI 304 stainless steel, applied using high-velocity oxygen fuel spraying. The coatings were produced with varying silicon carbide concentrations (25%, 40%, 60% and 75%) to evaluate their effectiveness in enhancing corrosion resistance. Microstructural analyses were conducted using SEM and EDS, while corrosion behaviour was assessed through open-circuit potential and Tafel tests in a NaCl solution. The findings indicate that increasing the silicon carbide content increases surface roughness and coating thickness. Additionally, the corrosion results revealed that coatings with higher silicon carbide concentrations exhibited more negative potential values, indicating improved corrosion resistance due to passivation effects.