New Cermet Powders for HVOF Spraying with Improved Corrosion and Oxidation Resistance for Offshore, Mining and Power Generation Applications

The present study describes the development of agglomerated and sintered WC and Cr₃C₂ based cermet powders with complex and highly corrosion resistant Fe and Ni matrix alloys. In addition a Fe-Cr-C with a Ni matrix was tested as a potential low cost alternative to standard Cr₃C₂-NiCr powders. The powders were sprayed by HVOF using liquid and gaseous fuel. Microstructure and phase composition of the coatings were analyzed by microscopy and X-ray diffraction. The technical properties of the coatings were examined by hardness measurements, abrasive wear and cavitation tests as well as corrosion tests. The results were compared with state-of-the-art coatings of WC-Co-Cr 86/10/4 and Cr₃C₂-NiCr 75/25.