Abstract:
Detonation gun-sprayed coatings are known for their high density, high bond strength, moderate substrate
heating, superior surface finish, better wear/corrosion resistance, and low cost. In this study,
detonation gun-spraying technique was used to deposit Ni-20Cr coating on a commonly used boiler steel
ASTM A213 TP347H. The specimens with and without coating were subjected to cyclic oxidation testing
at an elevated temperature of 700 C in actual boiler environment to ascertain the usefulness of the
coating. The mass change technique was used to establish the kinetics of erosion-corrosion. XRD and
SEM/EDS techniques were used to analyze the exposed samples. The uncoated sample suffered from
erosion, and a significant mass loss was recorded. It was observed that overall mass loss was reduced by
83% and thickness loss by 53% after the application of the coating. The detonation gun-sprayed Ni-20 Cr
coating was found to be suitable to impart erosion resistance to the given steel in the actual boiler
environment.
