Abstract
The oxidation of two Fe−Nb alloys containing 15 and 30 wt.% Nb has been studied at 600–800°C under low oxygen pressures, similar to those prevailing in environments of the coal-gasification type. The reaction produced only an internal oxidation of niobium to form two niobium oxides (NbO2 and Nb2O5) and in some cases a double Fe−Nb oxide. The kinetics of this reaction were very slow at 600°C but rather fast at 700 and 800°C. A peculiar feature of the internal oxidation of these alloys is that the distribution of the internal oxides follows closely that of the Nb-rich phase in the original two-phase alloys. This behavior, as well as the lack of formation of external scales of niobium oxides, is mainly a result of the limited solubility of niobium in iron and of the consequent presence of two metal phases in the alloys.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Y. Niu, F. Gesmundo, and F. Viani,Corros. Sci. 36, 883 (1994).
Y. Niu, F. Gesmundo, and F. Viani,Corros. Sci. 36, 1885 (1994).
R. C. Svedberg, inProperties of High Temperature Alloys, Z. A. Foroulis and F. S. Pettit, eds. (The Electrochem. Soc., Princeton, NJ, 1977), p. 331.
G. Wang, R. Carter, and D. L. Douglass,Oxid. Met. 32, 273 (1989).
W. Kai, D. L. Douglass, and F. Gesmundo,Oxid. Met. 37, 189 (1992).
T. B. Massalski, J. L. Murry, L. H. Bennett, and H. Baker (eds.),Binary Alloy Phase Diagrams (ASM, Materials Park, 1986).
F. Gesmundo, Y. Niu, F. Viani, and F. Rizzo,Oxid. Met.
C. H. P. Lupis,Chemical Thermodynamic of Materials (Chap. VII) (North-Holland, New York, 1983).
R. S. Roth, J. R. Dennis, and H. F. McMurdie,Phase Diagrams for Ceramists (Vol. VI) (The American Ceramic Society, Westerville, 1987).
O. Kubaschewski,High Temp.-High Press. 4, 1 (1972).
F. Gesmundo, F. Viani, and Y. Niu,Oxid. Met. 42, 409 (1994).
F. Gesmundo, Y. Niu, and F. Viani,Oxid. Met. 43, 379 (1995).
F. Gesmundo, F. Viani, and Y. Niu,Oxid. Met.
R. A. Rapp,Corrosion 21, 382 (1965).
M. J. Monteiro, Y. Niu, F. Rizzo, and F. Gesmundo,Oxid. Met. 43, 527 (1995).
J. F. Oliveira, Y. Niu, F. Rizzo, and F. Gesmundo,Oxid. Met.
J. Paidassi, inL'Oxydation des Métaux (Vol. II), J. Bénard, ed. (Gauthier-Villars, Paris, 1964), p. 13.
S. Mrowec,Gas Corrosion of Metals (National Bureau of Standards, Warsaw, 1978).
F. S. Pettit and J. B. Wagner,Acta Met. 12, 35 (1964).
R. Bredesen and P. Kofstad,Oxid. Met. 34, 361 (1990).
R. Bredesen and P. Kofstad,Oxid. Met. 35, 107 (1991).
R. Bredesen and P. Kofstad,Oxid. Met. 36, 27 (1991).
P. Kofstad,High Temperature Corrosion (Elsevier, London, 1988).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rebelo, M.C., Niu, Y., Rizzo, F.C. et al. The oxidation of two Fe−Nb alloys under low oxygen pressures at 600–800°C. Oxid Met 43, 561–579 (1995). https://doi.org/10.1007/BF01046899
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01046899