Analysis of material degradation for uncoated and NiCoCrAlY cold spray coated Superfer 800H in the secondary chamber of medical waste incinerator

• Cold spray process is used to develop the NiCoCrAlY coatings on Superfer 800H.
• Coating is dense and hard.
• Coating protects the substrate against erosion–corrosion in secondary chamber of medical waste incinerator.
• Uncoated Superfer 800H shows high degradation rate due to active oxidation in the presence of chlorine.

NiCoCrAlY coating was deposited on Superfer 800H superalloy with cold spray process to reduce the degradation rate of substrate superalloy in actual medical waste incineration environment. Erosion–corrosion performance of uncoated and cold sprayed superalloy was evaluated in the secondary chamber of medical waste incinerator. The degradation rate of the specimens was assessed by measuring the thickness loss of the specimen after cyclic exposure for 1000 h in medical waste incineration environment. Average degradation rate for uncoated and cold sprayed superalloy was found to be 157.95 mpy and 36.56 mpy respectively. The better performance of cold spray coated specimen might be attributed to the formation of protective Al2O3 scale at the top of surface and dense structure of the deposit coating.