Corrosion of aluminides by molten nitrate salt
The corrosion of titanium-, iron-, and nickel-based aluminides by a highly aggressive, oxidizing NaNO{sub 3}(-KNO{sub 3})-Na{sub 2}O{sub 2} has been studied at 650{degree}C. It was shown that weight changes could be used to effectively evaluate corrosion behavior in the subject nitrate salt environments provided these data were combined with salt analyses and microstructural examinations. The studies indicated that the corrosion of relatively resistant aluminides by these nitrate salts proceeded by oxidation and a slow release from an aluminum-rich product layer into the salt at rates lower than that associated with many other types of metallic materials. The overall corrosion process and resulting rate depended on the particular aluminide being exposed. In order to minimize corrosion of nickel or iron aluminides, it was necessary to have aluminum concentrations in excess of 30 at. %. However, even at a concentration of 50 at. % Al, the corrosion resistance of TiAl was inferior to that of Ni{sub 3}Al and Fe{sub 3}Al. At higher aluminum concentrations, iron, nickel, and iron-nickel aluminides exhibited quite similar weight changes, indicative of the principal role of aluminum in controlling the corrosion process in NaNO{sub 3}(-KNO{sub 3})-Na{sub 2}O{sub 2} salts. 20 refs., 5 figs., 3 tabs.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- Sponsoring Organization:
- DOE/CE
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6767438
- Report Number(s):
- CONF-901008-5; ON: DE91001626
- Resource Relation:
- Conference: Fall meeting of the Minerals, Metals and Materials Society on physical metallurgy and materials in conjunction with materials week and the material applications and services exposition, Detroit, MI (USA), 7-11 Oct 1990
- Country of Publication:
- United States
- Language:
- English
Similar Records
Influence of compositional modifications on the corrosion of iron aluminides of molten nitrate salts
Selection of corrosion-resistant materials for use in molten nitrate salts
Related Subjects
14 SOLAR ENERGY
ALUMINIUM ALLOYS
CORROSION
IRON BASE ALLOYS
NICKEL BASE ALLOYS
POTASSIUM NITRATES
CORROSIVE EFFECTS
SODIUM NITRATES
TITANIUM ALLOYS
CORROSION RESISTANCE
MICROSTRUCTURE
OXIDATION
SCALING
SODIUM OXIDES
SOLAR RECEIVERS
WEIGHT
ALKALI METAL COMPOUNDS
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
IRON ALLOYS
NICKEL ALLOYS
NITRATES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
SODIUM COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion
140700 - Solar Thermal Power Systems