Investigation Into the Suitability of HVOF Nickel Based Cermets in Marine Hydraulic Service Subject to Biofouling

A study was conducted into the use of HVOF coatings on hydraulic cylinder rods in marine environments subject to both biofouling and corrosion. The study comprised a laboratory phase for candidate material selection and HVOF process optimisation. This was followed by long term field testing of the most promising candidates, which were subsequently assessed based on corrosion, adhesion, surface roughness and hydraulic sealing performance. Two candidates, nickel based WC cermet coatings, WC–10Ni5Cr and WC–18Hastelloy C, showed excellent results, and are considered as candidates for the application.