Oxidation of Metals

, Volume 14, Issue 3, pp 217–234 | Cite as

The early stages of development of α-Al2O3 scales on Fe-Cr-Al and Fe-Cr-Al-Y Alloys at high temperature

  • F. A. Golightly
  • G. C. Wood
  • F. H. Stott


The development ofthe oxides on Fe-14%Cr-4%Al, Fe-27%Cr-4%Al, and similar alloys containing 0.008% Y, 0.023% Y, and 0.8% Y has been investigated during the early stages of oxidation in 1 atm oxygen at 1000 and 1200°C. In all cases, a steady-state α-Al2O3layer is established rapidly, after some initial formation of transient oxides rich in iron and chromium. For the yttrium-free alloys the steady-state situation is achieved more rapidly for the higher chromium-containing alloy and at the higher temperature. The amount of transient oxide formed is also determined by the specimen surface topography since the development of the α-Al2O3 layer is less rapid at the base of alloy asperities than at a flat alloy-oxide interface. Following establishment of the complete α-Al2O3layer, the oxide develops a convoluted oxide morphology at temperature, due to high compressive growth stresses in the oxide. These arise following reaction between oxygen ions diffusing inward down the oxide grain boundaries and aluminum ions diffusing outward through the bulk oxide. This results in lateral growth of the oxide and plastic deformation and movement of the alloy in a direction parallel to the alloy-oxide interface. The addition of yttrium to the alloys promotes the selective oxidation of aluminum. Also, the yttrium is incorporated into the growing oxide where it changes the mechanism of growth, reducing the production of the high compressive growth stresses and thus the development of the convoluted oxide morphology.

Key words

alumina transient oxidation yttrium 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J. K. Tien and F. S. Pettit,Metall. Trans. 3, 1587 (1972).Google Scholar
  2. 2.
    A. Kumar, M. Hasrallah, and D. L. Douglass,Oxid. Met. 8, 227 (1974).Google Scholar
  3. 3.
    I. M. Allam, D. P. Whittle, and J. Stringer,Oxid. Met. 12, 35 (1978).Google Scholar
  4. 4.
    F. A. Golightly, F. H. Stott, and G. C. Wood,Oxid. Met. 10, 163 (1976).Google Scholar
  5. 5.
    I. A. Kvernes,Oxid. Met. 6, 45 (1973).Google Scholar
  6. 6.
    B. Chattopadhyay and G. C. Wood,Oxid. Met. 2, 373 (1970).Google Scholar
  7. 7.
    B. H. Kear, L. P. Lemaire, D. E. Fornwalt, and F. S. Pettit,Oxid. Met. 3, 557 (1971).Google Scholar
  8. 8.
    I. G. Wright, B. A. Wilcox, and R. I. Jaffee, Final Report, Contract No. N62269-73-C-0327.Google Scholar
  9. 9.
    F. S. Pettit,Trans. Am. Inst. Min. Metall. Pet. Eng. 239, 1296 (1967).Google Scholar
  10. 10.
    J. Stringer, B. A. Wilcox, and R. I. Jaffee,Oxid. Met. 5, 11 (1972).Google Scholar
  11. 11.
    J. Stringer and I. G. Wright,Oxid. Met. 5, 59 (1972).Google Scholar
  12. 12.
    F. A. Golightly, F. H. Stott, and G. C. Wood,J. Electrochem. Soc. 126, 1035 (1979).Google Scholar
  13. 13.
    C. S. Giggins and F. S. Pettit, Aerospace Res. Labs. Report No. ARL 75-0234 (June 1975).Google Scholar
  14. 14.
    C. S. Giggins, B. H. Kear, F. S. Pettit, and J. K. Tien,Metall. Trans. 5, 1685 (1974).Google Scholar
  15. 15.
    V. R. Howes,Corros. Sci. 8, 729 (1968).Google Scholar
  16. 16.
    F. H. Stott, G. C. Wood, and F. A. Golightly,Corros. Sci. 19, 869 (1979).Google Scholar

Copyright information

© Plenum Publishing Corporation 1980

Authors and Affiliations

  • F. A. Golightly
    • 1
  • G. C. Wood
    • 1
  • F. H. Stott
    • 1
  1. 1.Corrosion and Protection CentreUniversity of Manchester Institute of Science and TechnologyManchesterEngland

Personalised recommendations