Abstract
The oxidation behavior of iron-aluminide coatings, Fe 3Al or (Fe,Ni) 3Al, produced by chemical-vapor deposition (CVD) was studied in the temperature range of 700-800°C in air + 10 vol.% H 2O. A typical ferritic steel, Fe-9Cr-1Mo, and an austenitic stainless steel, 304L, were coated. For both substrates, the as-deposited coating consisted of a thin (< 5μm), Al-rich outer layer above a thicker (30-50 μm), lower-Al-content inner layer. In addition to coated and uncoated Fe-9Cr-1Mo and 304L, cast Fe-Al model alloys with similar Al contents (13-20 at.%) to the CVD coatings were included in the oxidation exposures for comparison. The specimens were cycled to 1000 1 hr cycles at 700°0C and 500 1 hr cycles at 800°C, respectively. The CVD coating specimens showed excellent performance in the water-vapor environment at both temperatures, while the uncoated alloys were severely attacked. These results suggest that an aluminide coating can substantially improve resistance to water-vapor attack under these conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 103-120 |
| Number of pages | 18 |
| Journal | Oxidation of Metals |
| Volume | 62 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Aug 2004 |
Funding
The authors acknowledge K. M. Cooley, L. Walker, L. D. Chitwood, and G. W. Garner at ORNL for assisting with the experimental work. Thanks are extended to I. G. Wright at ORNL for reviewing the manuscript. Research was sponsored by the U.S. Department of Energy, Fossil Energy Advanced Materials Research Program, under contract DE-AC05-00OR22725 with UT-Battelle LLC and subcontract 4000007035 with Tennessee TechnologicaI University.
| Funders | Funder number |
|---|---|
| Fossil Energy Advanced Materials Research Program | DE-AC05-00OR22725 |
| Tennessee TechnologicaI University | |
| U.S. Department of Energy | |
| UT-Battelle | 4000007035 |
Keywords
- Coatings
- Ferritic steel
- Iron aluminide
- Stainless steel
- Water vapor