Abstract:
High temperature corrosion of metals and alloys can be controlled by the use of inhibitors. In this
work, the role of a superficially applied CeO2 coating to combat high temperature corrosion of some super
alloys such as Superfer 800H (Alloy A), Superco 605 (Alloy B) and Superni 75 (Alloy C) has been investi
gated. An accelerated corrosion testing of the coated as well as bare superalloys was done in a molten salt envi
ronment (Na2SO4–60% V2O5) at 900°C for 50 cycles. The weight change, Xray diffraction (XRD), Scan
ning Electron Microscopy (SEM) and Electron Probe MicroAnalysis (EPMA) of the exposed specimens
were carried out to characterize the oxide scales. The percentage decrease in the weight gain in alloys A, B
and C, with superficially applied CeO2, was found to be 23, 35 and 68%, respectively. It was concluded that
ceria (ceric oxide) was most effective in reducing the corrosion rate in alloy C.
