Hot Corrosion Resistant Cermet Coatings For Marine Diesel Engines

Wednesday, May 13, 2015
Exhibit Halls A&B (Long Beach Convention and Entertainment Center)
Dr. Francesco Marra , INSTM - National Interuniversity Consortium of Materials Science and Technology, Florence, Italy
Dr. Giovanni Pulci , INSTM - National Interuniversity Consortium of Materials Science and Technology, Florence, Italy
Lidia Baiamonte , INSTM - National Interuniversity Consortium of Materials Science and Technology, Florence, Italy
Stefano Gazzola , Zanzi, Ivrea, Italy
Patrizio Giovanetto , Zanzi, Ivrea, Italy
Prof. Cecilia Bartuli , INSTM - National Interuniversity Consortium of Materials Science and Technology, Florence, Italy
Prof. Teodoro Valente , INSTM - National Interuniversity Consortium of Materials Science and Technology, Florence, Italy
Diesel engines for marine and power generation applications are generally affected by severe hot corrosion phenomena, due to fuels (e.g. HFO, Heavy Fuel Oil) with high content of impurities and corrosive compounds. Exhaust valves are components that need protective coatings having to withstand hot and highly corrosive combustion gases.

In this work, five different coatings were produced and characterized: four commercial compositions (Cr3C2-NiCr, Cr3C2-self fusing alloy, Cr3C2-NiCrAlY, Cr3C2-CoNiCrAlY) were deposited by HVOF and APS, optimizing the deposition parameters by DOE technique. A new composite powder, composed by ceramic fillers, silica nanoparticles and a NiCr matrix, was developed and the related coating deposited.

Characterization of coatings was carried out in terms of microstructural features (porosity, composition, phases distribution, microhardness) and resistance in hot corrosion tests: samples were covered by a mixture of Na2SO4 and V2O5 and exposed at 750 °C in air.

See more of: Poster Session
See more of: Posters