Oxidation of Superalloys in Extreme Environments
- ORNL
Superalloys like 718 and its derivatives primarily rely on the formation of an external Cr-rich oxide layer or scale for environmental protection at high temperatures. Operating conditions where environmental resistance is more of a concern generally involve higher temperatures or more corrosive environments, especially where S is present, usually due to fuel impurities. With clean fuels, the presence of water vapor and oxygen, such as a combustion environment in a natural gas-fired turbine, chromia forms a volatile oxy-hydroxide leading to accelerated Cr loss. In laboratory experiments, mass losses are measured due to this volatilization. For sulfidizing or hot corrosion environments, the role of alloy and coating composition on corrosion resistance will be reviewed. An increasing area of interest is the interaction between environmental degradation and the stress-induced deformation of the superalloy including the influence of oxidation-resistant coatings on mechanical properties. Strategies to study this interaction will be discussed.
- Research Organization:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Organization:
- FE USDOE - Office of Fossil Energy (FE)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 985774
- Country of Publication:
- United States
- Language:
- English
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