Oxidation of Metals

, Volume 75, Issue 3–4, pp 143–166

Sub-Scale Depletion and Enrichment Processes During High Temperature Oxidation of the Nickel Base Alloy 625 in the Temperature Range 900–1000 °C

  • A. Chyrkin
  • P. Huczkowski
  • V. Shemet
  • L. Singheiser
  • W. J. Quadakkers
Original Paper

Abstract

Numerous chromia-forming austenitic steels and nickel-base alloys contain chromium-rich strengthening precipitates, e.g. chromium-base carbides. During high temperature exposure the formation of the chromia base oxide scale results in chromium depletion in the alloy matrix and consequently in dissolution of the strengthening phase in the sub-surface zone. The present study describes the oxidation induced phase changes in the chromium depletion layer in case of alloy 625, a nickel base alloy in which the strengthening precipitates contain hardly any or only minor amounts of chromium. Specimens of alloy 625 were subjected to oxidation up to 1000 h at 900 and 1000 °C and analyzed in respect to oxide formation and microstructural changes using light optical microscopy, scanning electron microscopy, energy and wavelength dispersive analysis, glow discharge optical emission spectroscopy, and X-ray diffraction. In spite of the fact that the alloy precipitates δ-Ni3Nb and/or (Ni, Mo)6C contain only minor amounts of chromium, the oxidation induced chromium depletion results in formation of a wide sub-surface zone in which the precipitate phases are depleted. However, in parallel, substantial niobium diffusion occurs towards the alloy surface resulting in formation of a thin layer of δ-Ni3Nb phase adjacent to the alloy/oxide interface. By modeling phase equilibria and diffusion processes using Thermo-Calc and DICTRA it could be shown that the phase changes in the sub-scale zone are governed by the influence of alloy matrix chromium concentration on the thermodynamic activities of the other alloying elements, mainly niobium and carbon. The δ-phase depletion/enrichment process is caused by a decreasing niobium activity with decreasing chromium concentration whereas the (Ni,Mo)6C dissolution finds its cause in the increasing carbon activity with decreasing chromium content.

Keywords

High temperature oxidation Ni-base alloy Phase transformations Modeling Chromium depletion Niobium enrichment Uphill-diffusion 

References

  1. 1.
    D. P. Whittle, D. J. Evans, D. B. Scully, and G. C. Wood, Acta Metallurgica 15, 1421 (1967).CrossRefGoogle Scholar
  2. 2.
    B. D. Bastow, D. P. Whittle, and G. C. Wood, Oxidation of Metals 12, 413 (1978).CrossRefGoogle Scholar
  3. 3.
    J. P. T. Vossen, P. Gawenda, K. Rahts, M. Rohrig, M. Schorr, and M. Schütze, Materials at High Temperatures 14, 387 (1997).Google Scholar
  4. 4.
    R. Bauer, M. Baccalaro, L. P. H. Jeurgens, M. Pohl, and E. J. Mittemeijer, Oxidation of Metals 69, 265 (2008).CrossRefGoogle Scholar
  5. 5.
    H. E. Evans and A. T. Donaldson, Oxidation of Metals 50, 457 (1998).CrossRefGoogle Scholar
  6. 6.
    W. J. Quadakkers and K. Bongartz, Werkstoffe und Korrosion 45, 232 (1994).CrossRefGoogle Scholar
  7. 7.
    P. Kofstad, High Temperature Oxidation, (Elsevier Applied Science, London and New York, 1988).Google Scholar
  8. 8.
    C. Wagner, Journal of the Electrochemical Society 103, 571 (1956).CrossRefGoogle Scholar
  9. 9.
    S. Kihara, J. B. Newkirk, A. Ohtomo, and Y. Saiga, Metallurgical Transactions A 11, 1019 (1980).CrossRefGoogle Scholar
  10. 10.
    T. Sourmail, Materials Science and Technology 17, 1 (2001).Google Scholar
  11. 11.
    P. J. Ennis, W. J. Quadakkers, and H. Schuster, Journal de Physique IV 3, 979 (1993).Google Scholar
  12. 12.
    D. J. Young and B. Gleeson, Corrosion Science 44, 345 (2002).CrossRefGoogle Scholar
  13. 13.
    D. Naumenko, V. Shemet, L. Singheiser, and W. J. Quadakkers, Journal of Materials Science 44, 1687 (2009).CrossRefGoogle Scholar
  14. 14.
    W. G. Sloof and T. J. Nijdam, International Journal of Materials Research 100, 1318 (2009).Google Scholar
  15. 15.
    R. N. Durham, B. Gleeson, and D. J. Young, Oxidation of Metals 50, 139 (1998).CrossRefGoogle Scholar
  16. 16.
    P. Krukovsky, K. Tadlya, A. Rybnikov, V. Kolarik, and W. Stamm, in Diffusion in Materials: Dimat 2004, Pt 1 and 2 (Trans Tech Publications Ltd, Zurich-Uetikon, 2005) p. 985.Google Scholar
  17. 17.
    D. Renusch, M. Schorr, and M. Schütze, Materials and Corrosion 59, 547 (2008).CrossRefGoogle Scholar
  18. 18.
    K. V. Dahl, J. Hald, and A. Horsewell, in Diffusion in Solids and LiquidsMASS DIFFUSION, ed. A. Öchsner and J. Grácio (Trans Tech Publications Ltd, Stafa-Zurich, 2006), p. 73.Google Scholar
  19. 19.
    E. Y. Lee, D. M. Chartier, R. R. Biederman, and R. D. Sisson, Surface and Coatings Technology 32, 19 (1987).CrossRefGoogle Scholar
  20. 20.
    J. A. Nesbitt, Oxidation of Metals 44, 309 (1995).CrossRefGoogle Scholar
  21. 21.
    T. J. Nijdam and W. G. Sloof, Acta Materialia 56, 4972 (2008).CrossRefGoogle Scholar
  22. 22.
    R. Cozar and A. Pineau, Metallurgical Transactions 4, 47 (1973).CrossRefGoogle Scholar
  23. 23.
    M. D. Mathew, P. Parameswaran, and K. B. S. Rao, Materials Characterization 59, 2008 (508).CrossRefGoogle Scholar
  24. 24.
    J. Froitzheim, G. H. Meier, L. Niewolak, P. Ennis, H. Hattendorf, L. Singheiser, and W. J. Quadakkers, Journal of Power Sources 178, 163 (2008).CrossRefGoogle Scholar
  25. 25.
    P. D. Jablonski, C. J. Cowen, and J. S. Sears, Journal of Power Sources 195, 813 (2010).CrossRefGoogle Scholar
  26. 26.
    Z. G. Yang, G. G. Xia, C. M. Wang, Z. M. Nie, J. Templeton, J. W. Stevenson, and P. Singh, Journal of Power Sources 183, 660 (2008).CrossRefGoogle Scholar
  27. 27.
    V. Kochubey, H. Al Badairy, J. Le Coze, D. Naumenko, G. J. Tatlock, E. Wessel, and W. J. Quadakkers, Materials at High Temperatures 22, 461 (2005).CrossRefGoogle Scholar
  28. 28.
    H. Nickel, W. J. Quadakkers, and L. Singheiser, Analytical and Bioanalytical Chemistry 374, 581 (2002).CrossRefGoogle Scholar
  29. 29.
    B. Jansson, M. Schalin, M. Selleby, and B. Sundman, in Computer Software in Chemical and Extractive Metallurgy, ed. C. W. Bale and G. A. Irons (Canadian Inst Mining, Metallurgy and Petroleum, Montreal, 1993), p. 57.Google Scholar
  30. 30.
    A. Taylor and K. Sachs, Nature 169, 411 (1952).CrossRefGoogle Scholar
  31. 31.
    M. J. Godden and J. Beech, Journal of Metals 21, A43 (1969).Google Scholar
  32. 32.
    T. M. Williams and J. M. Titchmarsh, Journal of Nuclear Materials 87, 398 (1979).CrossRefGoogle Scholar
  33. 33.
    X. M. Guan and H. Q. Ye, Journal of Materials Science 15, 2935 (1980).CrossRefGoogle Scholar
  34. 34.
    S. Hamar-Thibault, N. Valignat, and S. Lebaili, in X-Ray Optics and Microanalysis, ed. P. B. Kenway (Manchester, 1992), p. 189.Google Scholar
  35. 35.
    S. Lebaili, J. Ajao, and S. Hamarthibault, Journal of Alloys and Compounds 188, 87 (1992).CrossRefGoogle Scholar
  36. 36.
    M. Sundararaman, L. Kumar, G. E. Prasad, P. Mukhopadhyay, and S. Banerjee, Metallurgical and Materials Transactions A 30, 41 (1999).CrossRefGoogle Scholar
  37. 37.
    H. M. Tawancy, I. M. Allam, and N. M. Abbas, Journal of Materials Science Letters 9, 343 (1990).CrossRefGoogle Scholar
  38. 38.
    E. Essuman, G. H. Meier, J. Zurek, M. Hansel, T. Norby, L. Singheiser, and W. J. Quadakkers, Corrosion Science 50, 1753 (2008).CrossRefGoogle Scholar
  39. 39.
    P. Huczkowski, S. Ertl, J. Piron-Abellan, N. Christiansen, T. Hofler, V. Shemet, L. Singheiser, and W. J. Quadakkers, Materials at High Temperatures 22, 253 (2005).CrossRefGoogle Scholar
  40. 40.
    W. E. Moddeman, S. M. Craven, and D. P. Kramer, Metallurgical Transactions A 17, 351 (1986).CrossRefGoogle Scholar
  41. 41.
    F. Delaunay, C. Berthier, M. Lenglet, and J. M. Lameille, Mikrochimica Acta 132, 337 (2000).CrossRefGoogle Scholar
  42. 42.
    E. N’Dah, M. P. Hierro, K. Borrero, and F. J. Perez, Oxidation of Metals 68, 9 (2007).CrossRefGoogle Scholar
  43. 43.
    A. Borgenstam, A. Engstrom, L. Hoglund, and J. Agren, Journal of Phase Equilibria 21, 269 (2000).CrossRefGoogle Scholar
  44. 44.
    L. S. Darken, Transactions of the American Institute of Mining and Metallurgical Engineers 180, 430 (1949).Google Scholar
  45. 45.
    H. Strandlund and H. Larsson, in Defects and Diffusion in Metalsan Annual Retrospective Vii, ed. D. J. Fisher (Trans Tech Publications Ltd, Zurich-Uetikon, 2004), p. 97.Google Scholar
  46. 46.
    P. Huczkowski, Forschungszentrum Jülich, Germany, Jülich, 2009, unpublished results.Google Scholar
  47. 47.
    M. Michalik, M. Hansel, J. Zurek, L. Singheiser, and W. J. Quadakkers, Materials at High Temperatures 22, 213 (2005).CrossRefGoogle Scholar
  48. 48.
    V. B. Trindade, U. Krupp, P. E. G. Wagenhuber, and H. J. Christ, Materials and Corrosion 56, 785 (2005).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • A. Chyrkin
    • 1
  • P. Huczkowski
    • 1
  • V. Shemet
    • 1
  • L. Singheiser
    • 1
  • W. J. Quadakkers
    • 1
  1. 1.Forschungszentrum Jülich GmbHInstitute for Energy Research (IEF-2)JülichGermany

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