Alloy development and processing of FeAl: An overview
In the last few years, considerable progress has been made in developing B2-phase FeAl alloys with improved weldability, room-temperature ductility, and high-temperature strength. Controlling the processing-induced microstructure is also important, particularly for minimizing trade-offs in various properties. FeAl alloys have outstanding resistance to high-temperature oxidation, sulfidation, and corrosion in various kinds of molten salts due to formation of protective Al{sub 2}O{sub 3} scales. Recent work shows that FeAl alloys are carburization-resistant as well. Alloys with 36 to 40 at. % Al have the best combination of corrosion resistance and mechanical properties. Minor alloying additions of Mo, Zr, and C, together with microalloying additions of B, produce the best combination of weldability and mechanical behavior. Cast FeAl alloys, with 200 to 400 {mu}m grain size and finely dispersed ZrC, have 2 to 5% tensile ductility in air at room-temperature, and a yield strength > 400 MPa up to about 700 to 750{degrees}C. Extruded ingot metallurgy (I/M) and powder metallurgy (P/M) materials with refined grain sizes ranging from 2 to 50 {mu}m, can have 10 to 15% ductility in air and be much stronger, and can even be quite tough, with Charpy impact energies ranging from 25 to 105 J at room-temperature. This paper highlights progress made in refining the alloy composition and exploring processing effects on FeAl for monolithic applications. It also includes recent progress on developing FeAl weld-overlay technology, and new results on welding of FeAl alloys. It summarizes some of the current industrial testing and interest for applications.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 448094
- Report Number(s):
- CONF-961017-17; ON: DE97003500; TRN: 97:001817
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) and Metals materials week, Cincinnati, OH (United States), 6-10 Oct 1996; Other Information: PBD: 1997
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
IRON ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
ALUMINIUM ALLOYS
INTERMETALLIC COMPOUNDS
CARBURIZATION
CORROSION RESISTANCE
DUCTILITY
GRAIN SIZE
OXIDATION
POWDER METALLURGY
SULFIDATION
WELDABILITY
YIELD STRENGTH
MOLYBDENUM ADDITIONS
ZIRCONIUM ADDITIONS
CARBON ADDITIONS
BORON ADDITIONS