Abstract
The effect of hydrogen on the fracture of a nickel-base superalloy, alloy X-750, was investigated in the HTH condition. The effect of hydrogen was examined through tensile testing incorporating observations from scanning electron microscopy and light microscopy. The ductility at 25 °C, as measured by elongation to failure for tensile specimens, was reduced from 21 pct for noncharged specimens to 7.3 pct for 5.7 ppm hydrogen and to 3.5 pct for 65 ppm hydrogen. The elongation to failure was a function of the strain rate and test temperature. For hydrogen-charged specimens, the elongation decreased as the strain rate decreased at a constant temperature, while for a constant strain rate and varying temperature, there was a maximum in embrittlement near 25 °C and no embrittlement at -196 °C. For the noncharged specimens, the elongation monotonically increased as temperature increased, while there was no noticeable effect of strain rate. Prestraining prior to charging dramatically decreased elongation after hydrogen charging. When the strain rate was increased on the prestrained specimens, more plastic deformation was observed prior to failure. Failure did not occur until the flow stress was reached, supporting the proposition that plasticity is required for failure. The intergranular failure mechanism in alloy X-750 was a microvoid initiation process at grain boundary carbides followed by void growth and coalescence. The void initiation strain, as determined from tensile data and from sectioning unfractured specimens, was observed to be much lower in the hydrogen-charged specimens as compared to noncharged specimens. The reduced ductility may be explained by either a reduction of the interfacial strength of the carbide-matrix interface or a local hydrogen pressure at the carbide-matrix interface.
Similar content being viewed by others
References
A.R. Mcllree:Proc. Int. Symp. Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors, NACE, Houston, TX, 1984, pp. 838–50.
C. Benhamou and P. Poitrenaud:Proc: 1986 Workshop on Advanced High Strength Materials, EPRI NP-6363, pp. 50–65.
C.A. Grove and L.D. Petzold:Corrosion of Nickel-Base Alloys, ASM, Mars, PA, 1985, pp. 165–80.
T. Yonezawa, K. Onimura, N. Sasaguri, H. Nakata, and H. Suskida:Proc. Int. Symp. on Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors, NACE, Houston, TX, 1984, pp. 345–67.
C.K. Elliott: Ph.D. Thesis, Massachusetts Institute of Technology, Cambridge, MA, 1985.
E.A. Steigerwald, F.W. Schaller, and A.R. Troiano:Trans. AIME, 1960, vol. 218, pp. 832–41.
R.A. Oriani and P.H. Josephic:Acta Metall., 1974, vol. 22, pp. 1065–74.
C.D. Beachem:Metall. Trans. A, 1972, vol. 3A, pp. 437–51.
J. Eastman, T. Matsumoto, N. Narita, F. Heubaum, and H.K. Birnbaum: inHydrogen Effects in Metals, A.W. Thompson and I.M. Bernstein, eds., TMS, Warrendale, PA, 1986, pp. 397–409.
I.M. Robertson and H.K. Birnbaum:Acta Metall., 1986, vol. 34, pp. 353–66.
D. Shih and H.K. Birnbaum: inModelling Environmental Effects on Crack Growth Processes, R.H. Jones and W. Gerberich, eds., TMS, New York, NY, 1986, pp. 355–69.
W.S. Walston, I.M. Bernstein, and A.W. Thompson:Metall. Trans. A, 1992, vol. 23A, pp. 1313–22.
T.D. Lee, T. Goldberg, and J.P. Hirth:Metall. Trans. A, 1979, vol. 10A, pp. 199–208.
J.E. Costa and A.W. Thompson:Metall. Trans. A, 1982, vol. 13A, pp. 1315–18.
C.A. Zapfe and C.E. Sims:Trans. AIME, 1963, vol. 11, pp. 225–70.
J.K. Tien, A.W. Thompson, I.M. Bernstein, and R.J. Richards:Metall. Trans. A, 1976, vol. 7A, pp. 821–29.
J.R. Low:Symp. on Relation of Properties to Microstructure, ASM, Cleveland, OH, 1954, p. 163.
O.H. Kriege and J.M. Baris:Trans. ASM, 1969, vol. 62, pp. 195–200.
J. Crank:Mathematics of Diffusion, Claredon Press, Oxford, United Kingdom, 1956.
D.M. Symons: Ph.D. Dissertation, Carnegie Mellon University, Pittsburgh, PA, 1994.
R.M. Latanision and M. Kurkela:Corrosion, 1983, vol. 39 (5), pp. 174–81.
N. Kishimoto, T. Tanabe, T. Suzuki, and H. Yoshida:J. Nucl. Mater., 1985, vol. 127, pp. 1–9.
E. Sirois, P. Sofronis, and H.K. Birnbaum:Parkins Symp. on Fundamental Aspects of Stress Corrosion Cracking, S.M. Bruemmer, E.I. Meletis, R.H. Jones, W.W. Gerberich, F.P. Ford, and R.W. Staehle, eds., TMS, Warrendale, PA, 1991, pp. 179–90.
J.C. Chesnutt and R.A. Spurting:Metall. Trans. A, 1977, vol. 8A, pp. 216–18.
L.M. Brown and J.D. Embury: inProc. 3rd Int. Conf. on Strength of Metals and Alloys, Iron and Steel Institute, London, 1975, pp. 164–69.
D.H. Lassila and H.K. Birnbaum:Acta Metall., 1987, vol. 35, p. 1815.
M.F. Ashby:Phil. Mag., 1966, vol. 14, pp. 1157–78.
M.R. Louthan: inHydrogen In Metals, I.M. Bernstein and A.W. Thompson, eds., ASM, Metals Park, OH, 1974, pp. 53–78.
A.S. Argon, J. Im, and R. Safoglu:Metall. Trans. A, 1975, vol. 6A, pp. 825–37.
A.S. Argon and J. Im:Metall. Trans. A, 1975, vol. 6A, pp. 839–51.
S.H. Goods, and L.M. Brown:Acta Metall., 1979, vol. 27, pp. 1–15.
S.V. Nair, R.R. Jensen, and J.K. Tien:Metall Trans. A, 1983, vol. 14A, pp. 385–93.
J.E. Angelo, N.R. Moody, and M.I. Baskes: Paper presented at the5th Int. Conf. on Hydrogen Effects on Materials Behavior, Moran, WY, Sept. 11–15, 1994, in press.
S.W. Smith and J.R. Scully: Paper presented at the5th Int. Conf. on Hydrogen Effects on Materials Behavior, Moran, WY, Sept. 11–15, 1994, in press.
G. Thomas: inHydrogen Effects in Metals, A.W. Thompson and I.M. Bernstein, eds., TMS, New York, NY, 1980, pp. 77–85.
J.J. Lewandowski and A.W. Thompson:Acta Metall., 1987, vol. 35 (7), pp. 1453–62.
A. Turnbull, R.G. Ballinger, I.S. Hwang, and R.M. Gates:Hydrogen Effects on Materials Behavior, A.W. Thompson and N.R. Moody, eds., TMS, New York, NY, 1990, pp. 121–30.
J.C.M. Li, R.A. Oriani, and L.S. Darken:Z. Phys. Chem. (N.F.), 1966, vol. 49, pp. 271–90.
B. Baranowski, S. Majchrzak, and T.B. Flanagan:J. Phys. F: Met. Phys., 1971, vol. 1, pp. 258–61.
K.N. Akhurst and T.J. Baker:Metall. Trans. A, 1981, vol. 12A, pp. 1059–70.
J.R. Rice and M.A. Johnson:Inelastic Behavior of Solids, M.F. Kannin, W.G. Adler, A.R. Rosenfield, and R.I. Jaffee, eds., McGraw-Hill, New York, NY, 1970, pp. 641–671.
E. Orowan:Trans. Inst. Eng. Shipbuilders Scot., 1945, vol. 89, pp. 162–215.
A.W. Thompson and J.F. Knott:Metall. Trans. A, 1993, vol. 24A, pp. 523–34.
A.W. Thompson:Acta Metall., 1983, vol. 31 (10), pp. 1517–23.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Symons, D.M., Thompson, A.W. The effect of hydrogen on the fracture of alloy x-750. Metall Mater Trans A 27, 101–110 (1996). https://doi.org/10.1007/BF02647750
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02647750