Abstract
Oxidation of the relatively simple, two-phase alloy Ni-70 wt.%Cr in oxygen between 1073 and 1473°K results in the formation of a Cr2O3 scale containing less than O.5 wt.% Ni in solid solution. The oxidation kinetics are irreproducible for an initial period, which is brief at 1073 and 1273°K but much more pronounced at 1473°K, both in duration and degree. This behavior is associated with the failure of the protective Cr2O3 scale. However, after longer periods a compact layer of Cr2O3 becomes established under isothermal conditions and results in a change to more reproducible kinetics, especially at 1073 and 1273°K. Oxidation causes chromium depletion and the formation of a single-phase zone which separates the scale and the two-phase bulk alloy. The depth of Cr2O3 internal oxide coincides with this zone. The oxidation behavior is compared with that of more Ni-rich, single-phase Ni-Cr alloys, with particular reference to the effects of the constitution of the underlying alloy and the integrity of the protective oxide.
Similar content being viewed by others
References
G. C. Wood and T. Hodgkiess,J. Electrochem. Soc. 113, 319 (1966).
N. Birks and H. Rickert,J. Inst. Met. 91, 308 (1962–1963).
T. Hodgkiess, Ph.D. thesis, University of Manchester (1967).
K. A. Hay, F. G. Hicks, and D. R. Holmes,Werkst. Korros. 11, 917 (1970).
D. G. Barnes, J. M. Calvert, K. A. Hay, and D. G. Lees,Philos. Mag. 28, 1303 (1973).
T. Hodgkiess, D. P. Whittle, G. C. Wood and B. D. Bastow,Oxid. Met. 12, 439 (1978).
D. Caplan and G. I. Sproule,Oxid. Met. 9, 459 (1975).
G. C. Wood, T. Hodgkiess, and D. P. Whittle,Corros. Sci. 6, 129 (1966).
C. S. Tedman,J. Electrochem. Soc. 114, 788 (1967).
G. C. Wood and T. Hodgkiess,Werkst. Korros. 23, 766 (1972).
F. A. Golightly, F. H. Stott, and G. C. Wood,Oxid. Met. 10, 163 (1976).
B. D. Bastow, D. P. Whittle, and G. C. Wood,Oxid. Met. 12, 413 (1978).
W. W. Smeltzer and D. P. Whittle,J. Electrochem. Soc. 125, 1116 (1978).
H. E. Evans, D. A. Hilton, and R. A. Holm,Oxid. Met. 10, 149 (1976).
J. G. Fountain, F. H. Stott, and G. C. Wood, to be published.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hodgkiess, T., Wood, G.C., Whittle, D.P. et al. The oxidation of Ni-70 wt.%Cr in oxygen between 1073 and 1473°K. Oxid Met 14, 263–277 (1980). https://doi.org/10.1007/BF00604568
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00604568