Evaluation of through-porosity of HVOF sprayed coating

Anticorrosion coatings must be impermeable to protect steel structures in marine environments. We evaluated the through-porosity of HastelloyC high-velocity oxyfuel (HVOF) sprayed coatings by quantitatively analyzing dissolved substances derived from coated steel during immersion in HCl solution. This enabled us to detect slight amounts of through-pores, which depended on the coating thickness and on the coatingʹs stacking structure. It also enabled us to separately calculate both coating through-porosity and corrosion resistance when electrochemical measurements could not selectively detect either of these properties.