High temperature corrosion properties of SiNx and CrNx coatings deposited by IBAD method

SiNx and CrNx coatings (thickness 1–2 μm) were deposited by IBAD method at a nitrogen ions energy of 90 keV on low-alloy, AISI 310 and 316 substrate. The samples were subjected to long-term high temperature corrosion tests at cycled reducing–oxidizing atmosphere and in air. Corrosion rate was evaluated gravimetrically. The corrosion rate of coated alloy steels was significantly decreased at temperatures up to 800 °C. At 900 °C exposure the nitrides were subjected to fast decomposition and oxidation.