Metallurgical and Materials Transactions A

, Volume 27, Issue 4, pp 1063–1071 | Cite as

An evaluation of the Fe-N phase diagram considering long-range order of N atoms in γ′-Fe4N1-x and ε-Fe2N1-z

  • Bart J. Kooi
  • Marcel A. J. Somers
  • Eric J. Mittemeijer
Physical Chemistry

Abstract

The chemical potential of nitrogen was described as a function of nitrogen content for the Fe-N phases α-Fe[N], γ′-Fe4N1-x, and ε-Fe2N1-z. For α-Fe[N], an ideal, random distribution of the nitrogen atoms over the octahedral interstices of the bcc iron lattice was assumed; for γ′-Fe4N1-x. and ε-Fe2N1-z, the occurrence of a long-range ordered distribution of the nitrogen atoms over the octahedral interstices of the close packed iron sublattices (fcc and hcp, respectively) was taken into account. The theoretical expressions were fitted to nitrogen-absorption isotherm data for the three Fe-N phases. The α/α+ γ′, α +γ′/γ′, γ′/γ′ + ε, andγ′ + ε/ε phase boundaries in the Fe-N phase diagram were calculated from combining the quantitative descriptions for the absorption isotherms with the known composition of NH3/H2 gas mixtures in equilibrium with coexisting α andγ′ phases and in equilibrium with coexistingγ′ and ε phases. Comparison of the present phase boundaries with experimental data and previously calculated phase boundaries showed a major improvement as compared to the previously calculated Fe-N phase diagrams, where long-range order for the nitrogen atoms in theγ′ and ε phases was not accounted for.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Source Book on Nitriding, ASM, Metals Park, OH, 1977.Google Scholar
  2. 2.
    K.H. Jack:Proc. R. Soc. London, 1951, vol. A208, pp. 200–15.Google Scholar
  3. 3.
    N. DeCristofaro and R. Kaplow:Metall. Trans. A., 1977, vol. 8A, pp. 35–44.Google Scholar
  4. 4.
    R. Bril:Z. Krystallogr., 1928, vol. 69, pp. 26–34.Google Scholar
  5. 5.
    G. Hägg:Nova Acta Reg. Soc. Sci. Upsaliensis, 1929, vol. 7 (1), pp. 6–22.Google Scholar
  6. 6.
    S.B. Hendricks and P.B. Kosting:Z. Kristallogr., 1930, vol. 74, pp. 511–33.Google Scholar
  7. 7.
    K.H. Jack:Proc. R. Soc. London, 1948, vol. A195, pp. 34–55.Google Scholar
  8. 8.
    K.H. Jack:Acta Cryst., 1952, vol. 5, pp. 404–11.CrossRefGoogle Scholar
  9. 9.
    N. DeCristofaro and R. Kaplow:Metall. Trans. A, 1977, vol. 8A, pp. 425–30.Google Scholar
  10. 10.
    P. Rochegude and J. Foct:Phys. Status Solidi A, 1986, vol. 98, pp. 51–62.CrossRefGoogle Scholar
  11. 11.
    B.J. Kooi, M.A.J. Somers, and E.J. Mittemeijer:Metall. Mater Trans. A, 1994, vol. 25A, pp. 2797–2814.CrossRefGoogle Scholar
  12. 12.
    B.J. Kooi, M.A.J. Somers, and E.J. Mittemeijer:Metall. Trans. A, 1996, vol. 26A, pp. XXX-XXX.Google Scholar
  13. 13.
    M.A.J. Somers, B.J. Kooi, L. Maldzinski, E.J. Mittemeijer, A.A. van der Horst, A.M. van der Kraan, and N.M. van der Pers: Delft University of Technology, Delft, unpublished research, 1994.Google Scholar
  14. 14.
    M. Hillert and M. Jarl:Metall. Trans. A, 1975, vol. 6A, pp. 553–59.Google Scholar
  15. 15.
    J. Ågren:Metall. Trans. A, 1979, vol. 10A, pp. 1847–52.Google Scholar
  16. 16.
    J. Kunze:Steel Res., 1986, vol. 57 (8), pp. 361–67.Google Scholar
  17. 17.
    J. Kunze:Nitrogen and Carbon in Iron and Steels;Thermodynamics, Akademie Verlag, Berlin, 1990.Google Scholar
  18. 18.
    K. Frisk:CALPHAD, 1991, vol. 15 (1), pp. 79–106.CrossRefGoogle Scholar
  19. 19.
    H. Du:J. Phase Equilibria, 1993, vol. 14, pp. 682–93.Google Scholar
  20. 20.
    A.F. Guillemet and H. Du:Z. Metallkd., 1994, vol. 85, pp. 154–63.Google Scholar
  21. 21.
    H.A. Wriedt, N.A. Gokcen, and R.H. Nafziger:Bull. Alloy Phase Diagrams, 1987, vol. 8 (4), pp. 355–77.Google Scholar
  22. 22.
    W.S. Gorsky:Z. Phys., 1928, vol. 50, p. 64; W.L. Bragg and E.J. Williams:Proc. R. Soc. London, 1934, vol. A145, p. 699; W.L. Bragg and E.J. Williams:Proc. R. Soc. London, 1935, vol. A151, p. 540; W.L. Bragg and E.J. Williams:Proc. R. Soc. London, 1935, vol. A152, p. 231.CrossRefGoogle Scholar
  23. 23.
    E. Lehrer:Z. Elektrochem., 1930, vol. 36 (6), pp. 383–92.Google Scholar
  24. 24.
    Z. Przylecki and L. Maldzinski:Carbides, Nitrides and Borides, Proc. 4th Int. Conf., Politechnika Poznanska, 1987, pp. 153–62.Google Scholar
  25. 25.
    L. Maldzinski: Ph.D. Thesis, Politechnika Poznanska, Poland, 1989 (in Polish).Google Scholar
  26. 26.
    P.H. Emmett, S.B. Hendricks, and S. Brunauer:J. Am. Chem. Soc, 1930, vol. 52, pp. 1456–64.CrossRefGoogle Scholar
  27. 27.
    S. Brunauer, M.E. Jefferson, P.H. Emmett, and S.B. Hendricks:J. Am. Chem. Soc, 1931, vol. 53, pp. 1778–86.CrossRefGoogle Scholar
  28. 28.
    N.S. Corney and E.T. Turkdogan:J. Iron Steel Inst., 1955, vol. 180, pp. 344–48.Google Scholar
  29. 29.
    A. Burdese:Ann. Chim., 1959, vol. 49, pp. 1873–84.Google Scholar
  30. 30.
    H.J. Grabke:Ber. Bunsengesell. Phys. Chem., 1969, vol. 73 (6), pp. 596–601.Google Scholar
  31. 31.
    H.A. Wriedt, N.A. Gokcen, and R.H. Nafziger:Binary Alloy Phase Diagrams, ASM, Materials Park, OH, 1990, vol. 2, pp. 1728–30.Google Scholar
  32. 32.
    H.H. Podgurski and F.N. Davis:Acta Metall., 1981, vol. 29, pp. 1–9.CrossRefGoogle Scholar
  33. 33.
    L.J. Dijkstra:Trans. AIME, 1949, vol. 185, pp. 252–60.Google Scholar
  34. 34.
    V.G. Paranjpe, M. Cohen, M.B. Bever, and C.F. Floe:Trans. AIME, 1950, vol. 188, pp. 261–67.Google Scholar
  35. 35.
    H.U. Åström:Arkiv Fysik, 1954, vol. 8 (49), pp. 495–502.Google Scholar
  36. 36.
    A. Burdese:Metall. Ital, 1955, vol. 8, pp. 357–61.Google Scholar
  37. 37.
    J.D. Fast and M.B. Verrijp:J. Iron Steel Inst, 1955, vol. 180, pp. 337–43.Google Scholar
  38. 38.
    R. Rawlings and D. Tambini:J. Iron Steel Inst., 1956, vol. 184, pp. 302–08.Google Scholar
  39. 39.
    M. Nacken and J. Rahmann:Arch. Eisenhüttenwes., 1962, vol. 33(2), pp. 131–40.Google Scholar
  40. 40.
    Y. Imai, T. Masumoto, and M. Sakamoto:Sci. Rep. Res. Inst., Tohoku Univ., Ser. A, 1968, vol. A20 (1), pp. 1–13.Google Scholar
  41. 41.
    K. Abiko and Y. Imai:Trans. Jpn. Inst. Met., 1977, vol. 18, pp. 113- 24.Google Scholar
  42. 42.
    O. Eisenhut and E. Kaupp:Z. Elektrochem., 1930, vol. 36 (6), pp. 392–404.Google Scholar
  43. 43.
    E. Lehrer:Z. Elektrochem., 1930, vol. 36 (7), pp. 460–73.Google Scholar
  44. 44.
    C. Guillaud and H. Creveaux:Comt. Rend. Acad. Sci. Paris, 1946, vol. 222, pp. 1170–72.Google Scholar
  45. 45.
    F.K. Naumann and G. Langenscheid:Arch. Eisenhüttenwes., 1965, vol. 36 (9), pp. 677–82.Google Scholar
  46. 46.
    H.A. Wriedt:Trans. AIME, 1969, vol. 243, pp. 43–46.Google Scholar
  47. 47.
    M.A.J. Somers and E.J. Mittemeijer:Metall. Trans. A, 1990, vol. 21A, pp. 189–204.Google Scholar
  48. 48.
    M.A.J. Somers and E.J. Mittemeijer:Metall. Trans. A, 1990, vol. 21A, pp. 901–12.Google Scholar
  49. 49.
    M.A.J. Somers, N.M. van der Pers, D. Schalkoord, and E.J. Mittemeijer:Metall. Trans. A, 1989, vol. 20A, pp. 1533–39.Google Scholar
  50. 50.
    A.M. Vredenberg, C.M. Pérez-Martin, J.S. Custer, D.O. Boerma, L.de Wit, F.W. Saris, N.M. van der Pers, Th.H. de Keijser, and E.J. Mittemeijer:J. Mater. Res., 1992, vol. 7 (10), pp. 2689–2712.Google Scholar
  51. 51.
    L. de Wit, Th. Weber, J.S. Custer, and F.W. Saris:Phys. Rev. Lett, 1994, vol. 72, pp. 3835–38.CrossRefGoogle Scholar
  52. 52.
    H.H. Podgurski and H.E. Knechtel:Trans. AIME, 1969, vol. 245, pp. 1595–1602.Google Scholar
  53. 53.
    H.J. Grabke:Ber. Bunsengesell. Phys. Chem., 1968, vol. 72 (4), pp. 533–41. $Google Scholar

Copyright information

© The Minerals, Metals & Material Society and ASM International 1996

Authors and Affiliations

  • Bart J. Kooi
    • 1
  • Marcel A. J. Somers
    • 2
  • Eric J. Mittemeijer
    • 2
  1. 1.Materials Science Centre, Department of Applied PhysicsUniversity of GroningenAW GroningenThe Netherlands
  2. 2.Laboratory of Materials ScienceDelft University of TechnologyAL DelftThe Netherlands

Personalised recommendations