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.
Similar content being viewed by others
References
Source Book on Nitriding, ASM, Metals Park, OH, 1977.
K.H. Jack:Proc. R. Soc. London, 1951, vol. A208, pp. 200–15.
N. DeCristofaro and R. Kaplow:Metall. Trans. A., 1977, vol. 8A, pp. 35–44.
R. Bril:Z. Krystallogr., 1928, vol. 69, pp. 26–34.
G. Hägg:Nova Acta Reg. Soc. Sci. Upsaliensis, 1929, vol. 7 (1), pp. 6–22.
S.B. Hendricks and P.B. Kosting:Z. Kristallogr., 1930, vol. 74, pp. 511–33.
K.H. Jack:Proc. R. Soc. London, 1948, vol. A195, pp. 34–55.
K.H. Jack:Acta Cryst., 1952, vol. 5, pp. 404–11.
N. DeCristofaro and R. Kaplow:Metall. Trans. A, 1977, vol. 8A, pp. 425–30.
P. Rochegude and J. Foct:Phys. Status Solidi A, 1986, vol. 98, pp. 51–62.
B.J. Kooi, M.A.J. Somers, and E.J. Mittemeijer:Metall. Mater Trans. A, 1994, vol. 25A, pp. 2797–2814.
B.J. Kooi, M.A.J. Somers, and E.J. Mittemeijer:Metall. Trans. A, 1996, vol. 26A, pp. XXX-XXX.
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E.J. Mittemeijer, A.A. van der Horst, A.M. van der Kraan, and N.M. van der Pers: Delft University of Technology, Delft, unpublished research, 1994.
M. Hillert and M. Jarl:Metall. Trans. A, 1975, vol. 6A, pp. 553–59.
J. Ågren:Metall. Trans. A, 1979, vol. 10A, pp. 1847–52.
J. Kunze:Steel Res., 1986, vol. 57 (8), pp. 361–67.
J. Kunze:Nitrogen and Carbon in Iron and Steels;Thermodynamics, Akademie Verlag, Berlin, 1990.
K. Frisk:CALPHAD, 1991, vol. 15 (1), pp. 79–106.
H. Du:J. Phase Equilibria, 1993, vol. 14, pp. 682–93.
A.F. Guillemet and H. Du:Z. Metallkd., 1994, vol. 85, pp. 154–63.
H.A. Wriedt, N.A. Gokcen, and R.H. Nafziger:Bull. Alloy Phase Diagrams, 1987, vol. 8 (4), pp. 355–77.
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.
E. Lehrer:Z. Elektrochem., 1930, vol. 36 (6), pp. 383–92.
Z. Przylecki and L. Maldzinski:Carbides, Nitrides and Borides, Proc. 4th Int. Conf., Politechnika Poznanska, 1987, pp. 153–62.
L. Maldzinski: Ph.D. Thesis, Politechnika Poznanska, Poland, 1989 (in Polish).
P.H. Emmett, S.B. Hendricks, and S. Brunauer:J. Am. Chem. Soc, 1930, vol. 52, pp. 1456–64.
S. Brunauer, M.E. Jefferson, P.H. Emmett, and S.B. Hendricks:J. Am. Chem. Soc, 1931, vol. 53, pp. 1778–86.
N.S. Corney and E.T. Turkdogan:J. Iron Steel Inst., 1955, vol. 180, pp. 344–48.
A. Burdese:Ann. Chim., 1959, vol. 49, pp. 1873–84.
H.J. Grabke:Ber. Bunsengesell. Phys. Chem., 1969, vol. 73 (6), pp. 596–601.
H.A. Wriedt, N.A. Gokcen, and R.H. Nafziger:Binary Alloy Phase Diagrams, ASM, Materials Park, OH, 1990, vol. 2, pp. 1728–30.
H.H. Podgurski and F.N. Davis:Acta Metall., 1981, vol. 29, pp. 1–9.
L.J. Dijkstra:Trans. AIME, 1949, vol. 185, pp. 252–60.
V.G. Paranjpe, M. Cohen, M.B. Bever, and C.F. Floe:Trans. AIME, 1950, vol. 188, pp. 261–67.
H.U. Åström:Arkiv Fysik, 1954, vol. 8 (49), pp. 495–502.
A. Burdese:Metall. Ital, 1955, vol. 8, pp. 357–61.
J.D. Fast and M.B. Verrijp:J. Iron Steel Inst, 1955, vol. 180, pp. 337–43.
R. Rawlings and D. Tambini:J. Iron Steel Inst., 1956, vol. 184, pp. 302–08.
M. Nacken and J. Rahmann:Arch. Eisenhüttenwes., 1962, vol. 33(2), pp. 131–40.
Y. Imai, T. Masumoto, and M. Sakamoto:Sci. Rep. Res. Inst., Tohoku Univ., Ser. A, 1968, vol. A20 (1), pp. 1–13.
K. Abiko and Y. Imai:Trans. Jpn. Inst. Met., 1977, vol. 18, pp. 113- 24.
O. Eisenhut and E. Kaupp:Z. Elektrochem., 1930, vol. 36 (6), pp. 392–404.
E. Lehrer:Z. Elektrochem., 1930, vol. 36 (7), pp. 460–73.
C. Guillaud and H. Creveaux:Comt. Rend. Acad. Sci. Paris, 1946, vol. 222, pp. 1170–72.
F.K. Naumann and G. Langenscheid:Arch. Eisenhüttenwes., 1965, vol. 36 (9), pp. 677–82.
H.A. Wriedt:Trans. AIME, 1969, vol. 243, pp. 43–46.
M.A.J. Somers and E.J. Mittemeijer:Metall. Trans. A, 1990, vol. 21A, pp. 189–204.
M.A.J. Somers and E.J. Mittemeijer:Metall. Trans. A, 1990, vol. 21A, pp. 901–12.
M.A.J. Somers, N.M. van der Pers, D. Schalkoord, and E.J. Mittemeijer:Metall. Trans. A, 1989, vol. 20A, pp. 1533–39.
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.
L. de Wit, Th. Weber, J.S. Custer, and F.W. Saris:Phys. Rev. Lett, 1994, vol. 72, pp. 3835–38.
H.H. Podgurski and H.E. Knechtel:Trans. AIME, 1969, vol. 245, pp. 1595–1602.
H.J. Grabke:Ber. Bunsengesell. Phys. Chem., 1968, vol. 72 (4), pp. 533–41. $
Author information
Authors and Affiliations
Additional information
BART J. KOOI, formerly Graduate Student, Laboratory of Materials Science, Delft University of Technology.
Rights and permissions
About this article
Cite this article
Kooi, B.J., Somers, M.A.J. & Mittemeijer, E.J. An evaluation of the Fe-N phase diagram considering long-range order of N atoms in γ′-Fe4N1-x and ε-Fe2N1-z . Metall Mater Trans A 27, 1063–1071 (1996). https://doi.org/10.1007/BF02649775
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02649775