Abstract
Turbines fired with hydrogen or syngas from coal gasification will have significantly higher water vapor contents in the combustion gas than natural gas fired turbines. The effect of increased water vapor on alumina-forming coatings and model alloys was investigated at 1100 °C in furnace cyclic testing. Increasing the water vapor content from 10% to 50 vol.% increased the amount of scale spallation on undoped alumina-forming alloys. Compared to dry O2, increased spallation was observed for β and γ/γ' phase coatings on the substrates of alloys 142 and N5. In all cases, the addition of water vapor appeared to reduce the formation of alumina whiskers and ridges at the scale-gas interface, but did not significantly change the alumina growth rate. The addition of water vapor may have a detrimental effect on the selective oxidation of Al in γ/γ' alloys and coatings.
Original language | English |
---|---|
Pages (from-to) | 3852-3856 |
Number of pages | 5 |
Journal | Surface and Coatings Technology |
Volume | 201 |
Issue number | 7 SPEC. ISS. |
DOIs | |
State | Published - Dec 20 2006 |
Funding
The author would like to thank J. Moser, K. Cooley, J. Vought, H. Longmire, L. Walker, T. Brummett and K. S. Reeves for assistance with the experimental work. M. P. Brady, S. Dryepondt and P. F. Tortorelli provided helpful comments on the manuscript. This research was sponsored by the U.S. Department of Energy, Office of Coal and Power R and D, Office of Fossil Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.
Keywords
- Aluminum oxide
- Chemical vapor deposition
- High temperature oxidation
- Platinum
- TEM
- Water vapor