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Growth of Small Fatigue Cracks in Incoloy-908

  • Z. Mei
  • C. Krenn
  • J. W. MorrisJr.
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

Fatigue crack growth rates at 298 and 77 K were determined from conventional long-crack growth test at constant R, closure-free long-crack growth test at constant Kmax, and direct observation of small surface cracks. It was observed that the growth of small surface cracks was influenced by grain boundaries and orientations, resulting in tortuous paths and discontinuous growth. Although some surface cracks grew slow or even became dormant while some grew rapidly, the average growth rate of many small surface cracks was close to the growth rate of a long crack. When crack length < 100 μm, the threshold cyclic stress intensity Kth for a small surface crack to grow was lower than those for either a long crack or a closure-free long crack to grow, while the threshold cyclic stress σth was relatively constant and close to the fatigue endurance limit. Therefore, the combination of the fatigue endurance limit of polished surface and the threshold cyclic stress intensity of long crack can be used to determined the safety criterion at 4.2 K against fatigue failure.

Keywords

Fatigue Crack Crack Length Crack Growth Rate Fatigue Crack Growth Crack Closure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    M.M. Morra, R.G. Ballinger and I.S. Hwang, Metall. Trans. A, Vol 23A, pp. 3177–3192, 1992.Google Scholar
  2. 2.
    The Behaviour of Short Fatigue Cracks, K.J. Miller and E.R. de los Rios, eds., Mechanical Engineering Publications Limited, London, 1986.Google Scholar
  3. 3.
    Fatigue Engng Mater. Structures,1991, vol. 14, no. 2/3, special issue on International Conference on Short Fatigue Cracks, The European Structural Integrity Society, December 10–14, 1990, Sheffield, U.K.Google Scholar
  4. 4.
    Small Fatigue Cracks, R.O. Ritchie and J. Lankford, eds., Metallurgical Society, Inc., Pennsylvania 15086, 1986.Google Scholar
  5. 5.
    R.O. Ritchie and J. Lankford, in Small Fatigue Cracks, R.O. Ritchie and J. Lankford, eds., Metallurgical Society, Inc., Pennsylvania 15086, 1986, pp. 1–5.Google Scholar
  6. 6.
    K.J. Miller, Fatigue Engng Mater. Structures, vol. 10, pp. 93–113, 1987.CrossRefGoogle Scholar
  7. 7.
    S. Suresh, and R.O. Ritchie: Int. Met. Rev., vol. 29, pp 445–476, 1984.Google Scholar
  8. 8.
    Z. Mei and I.W. Morris, Jr., Metall. Trans. A, vol. 24A, pp. 689–700, 1993.Google Scholar
  9. 9.
    W.A. Herman, R.W. Hertzberg, and R. Jaccard: Fatigue Engng Mater. Structures,vol. 11, pp. 303320, 1988.Google Scholar
  10. 10.
    Z. Mei and J.W. Morris, Jr., Metall. Trans. A,to be submitted.Google Scholar
  11. 11.
    I.S. Hwang, R.G. Ballinger, M.M. Morra and M.M. Steeves, Advances in Cryogenic Engineering, vol. 38A, pp 1–10, 1991.Google Scholar
  12. 12.
    Annual Book of ASTM Standards, E647–83, ASTM, Philadelphia, PA, 1983, pp. 739–759.Google Scholar
  13. 13.
    Metals Handbook, 9th ed., ASM, Metals Park, OH, 1985, vol. 8, pp. 386–402.Google Scholar
  14. 14.
    J.C. Newman, Jr. and I.S. Raju, Eng. Fracs. Mech., 1981, vol. 15, pp. 185–192.CrossRefGoogle Scholar
  15. 15.
    P.K. Liaw and W.A. Logsdon, Acta. Metall., 1988, vol. 36, pp. 1731–1744.CrossRefGoogle Scholar
  16. 16.
    T. Yokobori, S. Konosu, and A.T. Yokobori, Jr., Proceedings International Conference of Fracture, vol. 1, Pergamon Press, New York, 1978, p. 665.Google Scholar
  17. 17.
    S. Suresh and R.O. Ritchie in Fatigue Crack Growth Threshold: Concepts, D.L. Davidson and S. Suresh, eds., TMS-AIME, Warrendale, PA, 1984, pp,. 227–61.Google Scholar
  18. 18.
    S. Suresh, Metall. Trans. A, 1983, vol. 14, pp. 2375–2385.Google Scholar
  19. 19.
    B.A. Bilby, G.E. Cardew, and I.C. Howard, Fracture 1977, D.M.R. Taplin, ed., Univ. of Waterloo Press, 1977, vol. 3, pp. 197–200.Google Scholar
  20. 20.
    A.A. Khrapkov, Int. J. Fract. Mech., 1971, vol. 7, pp. 373–382.Google Scholar
  21. 21.
    D. Taylor and J.F. Knott, Fatigue Engng. Mater. Struct., 1981, vol. 4, pp. 147–55.CrossRefGoogle Scholar
  22. 22.
    J. Lankford and D.L. Davidson, in Small Fatigue Cracks R.O. Ritchie and J. Lankford, eds., Metallurgical Society, Inc., Pennsylvania 15086, 1986, pp. 51–71.Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • Z. Mei
    • 1
  • C. Krenn
    • 1
  • J. W. MorrisJr.
    • 1
  1. 1.Center for Advanced Materials, Lawrence Berkeley Laboratory and Department of Materials Science and Mineral EngineeringUniversity of CaliforniaBerkeleyUSA

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