Oxidation of Metals

, Volume 9, Issue 2, pp 181–214 | Cite as

The mechanisms of breakaway oxidation of three mild steels in high-pressure CO2 at 500°C

  • A. M. Pritchard
  • J. E. Antill
  • K. R. J. Cottell
  • K. A. Peakall
  • A. E. Truswell


The mechanisms of breakaway oxidation of a rimming steel, a low-alloy steel (1 Cr-0.5 Mo), and a free-cutting steel (En1A) have been studied in high-pressure CO2 at 500°C. Average compressive stresses up to 170–280 ton in−2. in the scale have been derived from foil elongation and creep data. Carbon contents of up to 6 and 15% of the weight gain have been found in protective and breakaway scale and are larger than previously reported.1 Most of the carbon is deposited near the scale-metal interface, showing that CO2 diffuses through the scale. Oxidation in CO2-tritiated water mixtures gives a maximum tritium content in the metal at 250–500 h, which declines thereafter. Treatment with some sulfur compounds before oxidation, or the presence of sulfur in the metal, reduces the rates of protective and breakaway oxidation in wet CO2 and carbon transfer to the metal, but not to the scale. It is proposed that breakaway is initiated by an effect of hydrogen such as the accumulation of hydrogenous gases at the scale-metal interface under pressures sufficient to rupture the inner scale. Carbon deposition may assist initiation, and is probably the main factor in propagating breakaway oxidation.

Key words

mild steel carbon dioxide oxidation mechanism breakaway oxidation 


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  1. 1.
    J. E. Antill, K. A. Peakall, and J. B. Warburton,Corrosion Sci. 8, 689 (1968).Google Scholar
  2. 2.
    J. E. Antill, C. S. Campbell, D. Goodison, W. B. Jepson, and C. G. Stevens,Proc. 3rd Geneva Conference on Peaceful Uses of Atomic Energy 9, 523 (1964).Google Scholar
  3. 3.
    G. B. Gibbs,Oxid. Met. 7, 173 (1973).Google Scholar
  4. 4.
    D. Goodison and R. J. Harris,Brit. Corrosion J. 4, 146 (1969).Google Scholar
  5. 5.
    C. G. Stevens and J. Board,Brit. Corrosion J. 4, 80 (1969).Google Scholar
  6. 6.
    C. Moore and T. Raine,Iron & Steel Institute Special Report No. 69, 136 (1961).Google Scholar
  7. 7.
    W. R. Price and I. Whittle,J. Iron Steel Inst. 205, 668 (1967).Google Scholar
  8. 8.
    R. B. Anderson,Catalysis, P. H. Emmett, Ed. (Reinhold, New York, 1956), Vol. 4, p. 29.Google Scholar
  9. 9.
    E. A. Evans,Tritium and Its Compounds (Butterworths, London, 1966).Google Scholar
  10. 10.
    M. C. Bloom and M. J. Krulfeld,J. Electrochem. Soc. 104, 264 (1957).Google Scholar
  11. 11.
    C. J. Smithells,Metals Reference Book, 4th edition (Butterworths, London, 1967), Vol. 3, p. 878.Google Scholar
  12. 12.
    R. F. Johnson, M. J. May, R. J. Truman, and J. Mickleraith,Iron & Steel Institute Publication No. 97, 229 (1967).Google Scholar
  13. 13.
    A. Brenner and S. Senderoff,J. Res. Natl. Bur. Std. 42, 89 (1949).Google Scholar
  14. 14.
    G. B. Gibbs,Phil. Mag. 13, 589 (1966).Google Scholar
  15. 15.
    D. W. James and G. M. Leak,Phil. Mag. 12, 491 (1965).Google Scholar
  16. 16.
    D. W. James and G. M. Leak,Phil. Mag. 14, 701 (1966).Google Scholar
  17. 17.
    J. Stringer,Corrosion Sci. 10, 513 (1970).Google Scholar
  18. 18.
    D. H. Bradhurst and J. S. Llewelyn Leach,J. Electrochem. Soc. 113, 1245 (1966).Google Scholar
  19. 19.
    J. S. Llewelyn Leach and P. Neufeld,Proc. Brit. Ceram. Soc. 6, 49 (1966).Google Scholar
  20. 20.
    J. D. Noden, C. J. Knights, and M. W. Thomas,Brit. Corrosion J. 3, 47 (1968).Google Scholar
  21. 21.
    J. B. Wachtman, Jr.,Bull. Am. Ceram. Soc. 46, 765 (1967).Google Scholar
  22. 22.
    C. O. Hulse, S. M. Copley, and J. A. Pask,J. Am. Ceram. Soc. 46, 317 (1963).Google Scholar
  23. 23.
    W. K. Appleby and R. F. Tylecote,Corrosion Sci. 10, 325 (1970).Google Scholar
  24. 24.
    D. Bruce and P. Hancock,J. Inst. Metals 97, 148 (1969).Google Scholar
  25. 25.
    G. B. Gibbs, M. R. Wootton, W. R. Price, and K. E. Hodgson,Oxid. Met. 7, 185 (1973).Google Scholar
  26. 26.
    V. R. Howes and C. N. Richardson,Corrosion Sci. 9, 385 (1969).Google Scholar
  27. 27.
    D. A. Vermilyea,J. Electrochem. Soc. 110, 345 (1963).Google Scholar
  28. 28.
    W. R. Ruston, M. Warzee, J. Hennaut, and J. Waty,Carbon 7, 47 (1969).Google Scholar
  29. 29.
    P. L. Surman and J. E. Castle,Corrosion Sci. 9, 771 (1969).Google Scholar
  30. 30.
    L. A. Haas, S. E. Khalafalla, and P. L. Weston, Jr.,US Bureau of Mines Report RI-7064 (Washington, D.C., 1968).Google Scholar
  31. 31.
    D. Goodison, R. J. Harris, and J. Goldenbaum,Brit. Corrosion J. 4, 293 (1969).Google Scholar
  32. 32.
    J. E. Castle and P. L. Surman,J. Phys. Chem. 71, 4255 (1967).Google Scholar
  33. 33.
    J. E. Draley and W. E. Ruther,J. Electrochem. Soc. 104, 329 (1957).Google Scholar
  34. 34.
    K. Sachs and M. Odgers,J. Iron Steel Inst. 196, 406 (1960).Google Scholar
  35. 35.
    B. Chew and F. T. Fabling,Metal Constr. Brit. Weld. J. 4, 132 (1972).Google Scholar

Copyright information

© Plenum Publishing Corporation 1975

Authors and Affiliations

  • A. M. Pritchard
    • 1
  • J. E. Antill
    • 1
  • K. R. J. Cottell
    • 1
  • K. A. Peakall
    • 1
  • A. E. Truswell
    • 1
  1. 1.Materials Development DivisionAERE HarwellDidcotEngland

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