Advertisement

Metallurgical and Materials Transactions A

, Volume 40, Issue 2, pp 321–329 | Cite as

Creep-Fatigue Interactions in a 9 Pct Cr-1 Pct Mo Martensitic Steel: Part I. Mechanical Test Results

  • B. FournierEmail author
  • M. Sauzay
  • C. Caës
  • M. Noblecourt
  • M. Mottot
  • L. Allais
  • I. Tournie
  • A. Pineau
Article

Abstract

Creep-fatigue (CF) tests are carried out on a modified 9 pct Cr-1 pct Mo (P91) steel at 550 °C. These CF tests are strain controlled during the cyclic part of the stress-strain hysteresis loop and then load controlled when the stress is maintained at its maximum value, to produce a prescribed value of the creep strain before cyclic deformation is reversed under strain-controlled conditions. The observed cyclic softening implies that the applied creep stress continuously decreases with the number of cycles. However, the minimum creep rates measured at the end of the holding periods do not decrease when the applied stress decreases. The minimum creep rates measured at the end of these tests can be hundreds of times faster than those observed for the as-received material. This acceleration of creep rates can be to the microstructural coarsening and to the decrease of the dislocation density observed after fatigue and CF loadings. Cyclic creep tests consisting of very long holding periods interrupted by unloading/reloading are also carried out. These results suggest that cyclic loadings affect the creep lifetime and flow behavior only if a plastic strain is applied during cycling. Creep tests carried out on a material cyclically prestrained and fatigue tests carried out on a material previously deformed in creep confirm that the deterioration of the mechanical properties is much faster in fatigue and CF compared to creep.

Keywords

Creep Rate Creep Test Creep Strain Creep Behavior Creep Deformation 
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.

NOMENCLATURE

PF

pure fatigue

CF

creep fatigue

RF

relaxation fatigue

Dc

creep damage

tf

creep lifetime

th

holding period duration

Nf

number of cycles to fracture

N

number of cycles

N50

number of cycles necessary to have a 50 pct decrease of the stress

σ

stress

ε

strain

T

temperature

R

stress ratio

Δεfat

fatigue strain range

Δεp

plastic strain range

εcreep

creep strain

\( \ifmmode\expandafter\dot\else\expandafter\.\fi{\varepsilon }_{s} \)

minimum creep rate

\( \ifmmode\expandafter\dot\else\expandafter\.\fi{\varepsilon }_{s} \)(N)

minimum creep rate after N cycles

\( \ifmmode\expandafter\dot\else\expandafter\.\fi{\varepsilon }^{{AR}}_{s} \)

minimum creep rate of the as-received material

Δσ

stress range

Notes

Acknowledgments

The direction of the Nuclear Energy of the CEA is acknowledged for financial support through the DDIN/SF project. The authors thank A.-F. Gourgues from Ecole des Mines for fruitful discussions.

References

  1. 1.
    E.E. Bloom, S.J. Zinkle, F.W. Wiffen: J. Nucl. Mater., 2004, vols. 329–333, pp. 12–19CrossRefGoogle Scholar
  2. 2.
    R.W. Swindeman, M.L. Santella, P.J. Maziasz, B.W. Roberts, K. Coleman: Press. Vess. Pip., 2004, vol. 81, pp. 507–12CrossRefGoogle Scholar
  3. 3.
    P.J. Ennis and W.J. Quadakkers: Parsons 2000 Advanced Materials for 21st Century Turbines and Power Plant, Proc. 5th Int. Charles Parsons Turbine Conf., Maney Publishing, London, 2000, pp. 265–74Google Scholar
  4. 4.
    S.R. Holdsworth: Mater. High Temp., 2001, vol. 18, pp. 261–65CrossRefGoogle Scholar
  5. 5.
    Design and Construction Rules for Mechanical Components, RCC-MR, CEA, France, 1993Google Scholar
  6. 6.
    Case N-47-29 Class 1 Components in Elevated Temperature Service, Section III, Division I. Cases of ASME Boiler and Pressure Vessel Code, ASME, 1990Google Scholar
  7. 7.
    R5 , Assessment Procedure for the High Temperature Response of Structures, British-Energy, 2003Google Scholar
  8. 8.
    M.T. Cabrillat, L. Allais, M. Mottot, B. Riou, and C. Escaravage: Proc. PVP2006-ICPVT-11, Vancouver, BC, Canada, 2006Google Scholar
  9. 9.
    B. Rezgui, P. Petrequin, and M. Mottot: Proc. ICF 5, Lonnas, France, 1994, pp. 2293–402Google Scholar
  10. 10.
    P. Skelton: Fatigue at High Temperature, Applied Science Publishers, 1982, ch. VIIGoogle Scholar
  11. 11.
    Y. Qin, G. Götz, W. Blum: Mater. Sci. Eng. A, 2003, vol. 341, pp. 211–15CrossRefGoogle Scholar
  12. 12.
    P. Polcik, T. Sailer, W. Blum, S. Straub, J. Bursik, A. Orlova: Mater. Sci. Eng. A, 1999, vol. 260, pp. 252–59CrossRefGoogle Scholar
  13. 13.
    F. Abe: Mater. Sci. Eng. A, 2004, vols. 387–389, pp. 565–69Google Scholar
  14. 14.
    S.H. Kim, B.J. Song, W.S. Ryu, J.H. Hong: J. Nucl. Mater., 2004, vols. 329–333, pp. 299–303CrossRefGoogle Scholar
  15. 15.
    J.S. Dubey, H. Chilukuru, J.K. Chakravartty, M. Schwienheer, A. Scholz, W. Blum: Mater. Sci. Eng. A, 2005, vol. 406, pp. 152–59CrossRefGoogle Scholar
  16. 16.
    M. Kimura, K. Yamaguchi, M. Hayakawa, K. Kobayashi, K. Kanazawa: Int. J. Fatigue, 2006, vol. 28, pp. 300–08CrossRefGoogle Scholar
  17. 17.
    A. Orlova, J. Bursik, K. Kucharova, V. Sklenicka: Mater. Sci. Eng. A, 1998, vol. 245, pp. 39–48CrossRefGoogle Scholar
  18. 18.
    E. Cerri, E. Evangelista, S. Spigarelli, P. Bianchi: Mater. Sci. Eng. A, 1998, vol. 245, pp. 285–92CrossRefGoogle Scholar
  19. 19.
    P.J. Ennis and A. Czyrska Filemonowicz: OMMI, 2002, vol. 1, www.ommi.co.uk
  20. 20.
    S. Kim, J.R. Weertman: Metall. Trans. A, 1988, vol. 19A, pp. 999–1007ADSGoogle Scholar
  21. 21.
    A. Kostka, K. Tak, R. Hellmig, Y. Estrin, G. Eggeler: Acta Mater., 2007, vol. 55, pp. 539–50CrossRefGoogle Scholar
  22. 22.
    F. Abe, S. Nakazawa, H. Araki, T. Noda: Metall. Trans. A, 1992, vol. 23A, pp. 469–77ADSGoogle Scholar
  23. 23.
    V. Shankar, M. Valsan, K. Bhanu Sankara Rao, R. Kannan, S.L. Mannan, S.D. Pathak: Mater. Sci. Eng. A, 2006, vol. 437, pp. 413–22CrossRefGoogle Scholar
  24. 24.
    A. Dronhofer, J. Pesicka, A. Dlouhy, G. Eggeler: Z. Metallkd., 2003, vol. 94, pp. 511–20Google Scholar
  25. 25.
    J.C. Earthman, G. Eggeler, B. Ilschner: Mater. Sci. Eng. A, 1989, vol. 110, pp. 103–14CrossRefGoogle Scholar
  26. 26.
    R. Vasina, P. Lukas, L. Kunz, V. Sklenicka: Fatigue Fract. Eng. Mater. Struct., 1995, vol. 18, pp. 27–35CrossRefGoogle Scholar
  27. 27.
    K. Kimura, K. Kushima, F. Abe, K. Suzuki, S. Kumai, and A. Satoh: Parsons 2000 Advanced Materials for 21st Century Turbines and Power Plant, Proc. 5th Int. Charles Parsons Turbine Conf., CEA, France, 2000, pp. 590–602Google Scholar
  28. 28.
    W.B. Jones, C.R. Hills, D.H. Polonis: Metall. Trans. A, 1991, vol. 22A, p. 1049ADSGoogle Scholar
  29. 29.
    B. Fournier, M. Sauzay, F. Barcelo, E. Rauch, A. Renault, T. Cozzika, and A. Pineau: Metall. Mater. Trans. A, 2008, DOI  10.1007/s11661-008-9687-y
  30. 30.
    A. Nagesha, M. Valsan, R. Kannan, K. Bhanu Sankara Rao, S.L. Mannan: Int. J. Fatigue, 2002, vol. 24, pp. 1285–93CrossRefGoogle Scholar
  31. 31.
    A.F. Armas, C. Petersen, R. Schmitt, M. Avalos, I. Alvarez-Armas: J. Nucl. Mater., 2002, vols. 307–311, pp. 509–13CrossRefGoogle Scholar
  32. 32.
    B. Fournier, M. Sauzay, C. Caës, M. Mottot: Mater. Sci. Eng. A, 2006, vol. 437, pp. 183–96CrossRefGoogle Scholar
  33. 33.
    B. Fournier, M. Sauzay, C. Caës, M. Noblecourt, M. Mottot, A. Pineau: Mater. Sci. Eng. A, 2006, vol. 437, pp. 197–211CrossRefGoogle Scholar
  34. 34.
    M. Sauzay, H. Brillet, I. Monnet, M. Mottot, F. Barcelo, B. Fournier, A. Pineau: Mater. Sci. Eng. A, 2005, vols. 400–401, pp. 241–44Google Scholar
  35. 35.
    M. Sauzay, B. Fournier, M. Mottot, A. Pineau, and I. Monnet: Mater. Sci. Eng. A, 2008, vols. 483–484, pp. 410–14Google Scholar
  36. 36.
    B. Fournier, M. Sauzay, C. Caës, M. Noblecourt, A. Bougault, V. Rabeau, A. Pineau: Int. J. Fatigue, 2008, vol. 30, pp. 663–76CrossRefGoogle Scholar
  37. 37.
    Creep & Fracture in High Temperature Components—Design & Life Assessment Issues, ECCC Creep Conf., London, 2005, I. Shibli, ed., Destech Publications, LancasterGoogle Scholar
  38. 38.
    B. Fournier, M. Sauzay, C. Caës, M. Noblecourt, A. Bougault, V. Rabeau, A. Pineau: Int. J. Fatigue, 2008, vol. 30, pp. 649–62CrossRefGoogle Scholar
  39. 39.
    V. Gaffard: Ph.D. Thesis, Ecole des Mines de Paris, Paris, 2005Google Scholar
  40. 40.
    V. Sklenicka, K. Kucharova, M. Svoboda, L. Kloc, J. Bursik, A. Kroupa: Mater. Charact., 2003, vol. 51, pp. 35–48CrossRefGoogle Scholar
  41. 41.
    F. Monkman, N. Grant: Proc. ASTM, 1956, vol. 56, pp. 593–620Google Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2008

Authors and Affiliations

  • B. Fournier
    • 1
    Email author
  • M. Sauzay
    • 1
  • C. Caës
    • 1
  • M. Noblecourt
    • 1
  • M. Mottot
    • 1
  • L. Allais
    • 1
  • I. Tournie
    • 1
  • A. Pineau
    • 2
  1. 1.CEA/DEN/DANS/DMN/SRMAGif-sur-Yvette CedexFrance
  2. 2.ENSMP, Centre des Matériaux P.-M. Fourt, UMR CNRS 7633EvryFrance

Personalised recommendations