Abstract
Recuperators for developmental high-efficiency small gas turbine engines will require low-cost materials with both creep and corrosion resistance at 700°C or higher. Because of the accelerated corrosion attack caused by water vapor in the exhaust gas and pressurized inlet air, alloys used in current recuperators, such as type 347 stainless steel, do not have sufficient oxidation resistance to meet lifetime goals at these higher temperatures. More highly alloyed steels and Ni-base alloys can meet the requirements but may be prohibitively expensive. Model Fe-Ni-Cr and Fe-Cr alloys are being tested in air plus 10% water vapor in order to determine compositions with appropriate environmental resistance for this application and to determine the effect of minor alloy additions. Results indicate that Ni and Cr contents in the 20wt.% range prevent accelerated attack observed in leaner alloys and that Si is the most critical minor (<0.5 wt.%) alloy addition for long-term oxidation resistance in these environments.
| Original language | English |
|---|---|
| Journal | NACE - International Corrosion Conference Series |
| Volume | 2003-April |
| State | Published - 2003 |
| Event | Corrosion 2003 - San Diego, United States Duration: Apr 16 2003 → Apr 20 2003 |
Funding
The authors wish to thank G. Garner at ORNL for performing the oxidation exposures, H. Longmire at ORNL for performing the metallography and L. Walker for performing the microprobe work. D. P. Stinton and I. G. Wright at ORNL reviewed the manuscript. The research was sponsored by the U.S. Department of Energy, Office of Power Technology, Distributed Energy Resources Program under contract DE-AC05-00OR22725 with UT-Battelle, LLC.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | DE-AC05-00OR22725 with UT-Battelle |
Keywords
- Alloy composition
- Gas turbines
- Recuperators
- Stainless steel
- Water vapor