Oxidation behavior of Ni-based coatings deposited by PTA on gray cast iron

► Higher arc current in PTA process increases dilution of Colmonoy coated cast iron. ► Coating produced with lower dilution exhibits more effective oxidation resistance. ► In low dilution samples, oxidation protection is achieved by a Si based oxide layer. ► Higher Fe content in the diluted zone has a harmful effect on oxidation resistance. ► Decarburization also accounts for the oxidation rate of high diluted coatings.