High Temperature Corrosion of Selected Thermally Sprayed Coatings Deposited by HVOF Technology

This paper summarizes the results of high-temperature corrosion and erosion tests conducted on a wide range of coating materials, including Cr₃C₂-NiCr, Cr₃C₂-CoNiCrAlY, TiMoCN-Ni, Stellite 6, NiCrBSi, and Hastelloy C-276. All coatings were deposited on stainless steel substrates by HVOF spraying, and after high-temperature testing, were evaluated by means of SEM and EDX analysis. Of the coating materials evaluated, Hastelloy C-276 provided the best protection against high-temperature corrosion. It also exhibited the highest erosion resistance at a particle impact angle of 90°, but at the sharpest impact angle of 15°, Cr₃C₂-NiCr coatings were found to be the most erosion resistant, likely due to the strong bonding of carbide particles in matrix. NiCrBSi coatings, on the other hand, exhibited the highest values of volume loss.