High-temperature alloys and thermal spray coatings for energy conversion systems
- CANMET, Ottawa, Ontario (Canada). Metals Technology Lab.
Materials continue to be of primary concern as the potential limiting factor for the implementation of coal gasification technology in Canada. Superalloys and thermal spray coatings for syngas coolers represent one class of materials where a knowledge of general trends in oxidation/sulphidation and erosion resistance for a range of chemical compositions is thought to be essential for reliable operation of such technology. Alloy 800H, 304, 310, T91, Monit and Sanicro 28 along with four types of coatings (Al{sub 2}O{sub 3}, Cr{sub 2}O{sub 3}, Al{sub 2}O{sub 3}/Ni3Al and CoCrAlYNi) applied on each one of the above alloys have been subjected to a series of exposures (6 {times} 250h cycles) in two different gas mixtures containing CO, H{sub 2}, H{sub 2}S, H{sub 2}O at 600 C. The kinetics and mechanisms of corrosion and erosion of these alloys have been investigated using Scanning Electron Microscopy and surface analytical techniques. Thermal spray coatings of ceramic and composite materials were found to be problematic on austenitic alloys because of spallation. Ceramic, composite and metallic coatings adhered well to the ferritic alloy. Nickel aluminide in combination with aluminum oxide as a composite did not display the expected high degree of corrosion resistance. High temperature erosion rates were found to be low on the bare superalloys and to be decreased by highly alloyed metallic coatings such as CoCrAlYNi, FeCrAlYMo and NiCrAlYCo. Ceramic and composite coatings were ineffective in reducing erosion rates because of spallation and reactivity in the simulated gasification environment.
- OSTI ID:
- 233974
- Report Number(s):
- CONF-950908--; ISBN 0-87170-539-7
- Country of Publication:
- United States
- Language:
- English
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Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers. Semiannual technical progress report, August 14, 1996--January 14, 1997
Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environment. Semi-annual report, August 14, 1996--January 14, 1997
Related Subjects
36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
CARBON MONOXIDE
CHROMIUM ALLOYS
CHROMIUM OXIDES
COAL GASIFICATION PLANTS
COBALT ALLOYS
COMPOSITE MATERIALS
CORROSION RESISTANCE
ELECTRON MICROPROBE ANALYSIS
EROSION
EXPERIMENTAL DATA
HEAT EXCHANGERS
HEAT RESISTING ALLOYS
HYDROGEN
HYDROGEN SULFIDES
KINETICS
NICKEL ALLOYS
OXIDATION
PLASMA ARC SPRAYING
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
SULFIDATION
WATER
YTTRIUM ALLOYS