Advertisement

Journal of Materials Science

, Volume 41, Issue 12, pp 3907–3915 | Cite as

A generalised Monkman-Grant relation for creep life prediction: An application to 1CrMoV rotor steel

  • M. Evans
Article

Abstract

A generalised Monkman—Grant relation, which can be derived from the 4-Θ projection technique, is proposed and then used to predict creep properties at non accelerated test conditions. In this generalisation, creep rates at low strains are used to predict minimum creep rates that are then used in the Monkman-Grant relation to predict times to failure. Predictions of creep properties for 1CrMoV from this generalisation and from the 4-Θ projection technique were assessed using the mean absolute percentage error (MAPE) and mean square error (MSE)—which was further decomposed into systematic and random components.

When considering the accuracy with which minimum creep rates were predicted, all but the generalised Monkman-Grant relation using 0.1% strain had a lower MAPE compared to the 4-Θprojection technique. The generalised Monkman-Grant relation using 0.5% and 1% strains had larger random components of the MSE compared to the 4-Θprojection technique. When considering the accuracy with which times to failure were predicted, all of the generalised Monkman-Grant relations produced lower MAPE compared to the 4-Θ projection technique. However, only when creep rates were measured at 0.2% strain, did the generalised Monkman-Grant relation produce prediction errors that had a significantly higher random component.

Keywords

Mean Square Prediction Error Creep Rate Mean Absolute Percentage Error Creep Curve Creep Property 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    M. EVANS, J. Mater Sci. 39 (2004) 2053.CrossRefGoogle Scholar
  2. 2.
    R. W. EVANS, Mat. Sci. Technol. 5 (1989) 699.Google Scholar
  3. 3.
    Idem. ibid. 16 (2000) 6.CrossRefGoogle Scholar
  4. 4.
    R. W. EVANS and P. J. SCHARNING, Mat. Sci. Technol., 17 (2001) 487.Google Scholar
  5. 5.
    L. M. KACHANOV, “The Theory of Creep” (National Lending Library, Boston Spa, UK, 1967).Google Scholar
  6. 6.
    Y. N. RABOTNOV, “Creep Problems in Structural Members” (North Holland, Amsterdam, 1969).Google Scholar
  7. 7.
    A. M. OTHMAN and D. R. HAYHURST, Int. J. Mech. Sci. 32(1) (1990) 35.CrossRefGoogle Scholar
  8. 8.
    M. PRAGER, The Omega Method—An Engineering Approach to Life Assessment. Journal of Pressure Vessels Technology 122 (2000) 273.CrossRefGoogle Scholar
  9. 9.
    R. W. EVANS and B. WILSHIRE, “Creep of Metals and Alloys (The Institute of Materials, London, 1985).Google Scholar
  10. 10.
    R. W. EVANS, M. R. WILLIS, B. WILSHIRE, S. HOLDSWORTH, B. SENIOR, A. FLEMING, M. SPINDLER and J. A. WILLIAMS, in Proceedings of the 5th International Conference on “Creep and Fracture of Materials and Structures”, Swansea, 1993, edited by B. Wilshire and R.W. Evans (The Institute of Materials, London, 1993) p. 633.Google Scholar
  11. 11.
    M. EVANS, J. Mater Sci. 35 (2000) 2937.CrossRefGoogle Scholar
  12. 12.
    F. C. MONKMAN and N. J. GRANT, edited by N. J. Grant and A. W. Mullendore (MIT Press, Boston, 1963) vol. 56.Google Scholar
  13. 13.
    F. DOBES and K. MILICKA, Met. Sci. 10 (1976) 382.Google Scholar
  14. 14.
    M. EVANS, Mater Sci. Technol. 15 (1999) 91.CrossRefGoogle Scholar
  15. 15.
    M. EVANS, in Proceeding of the International Conference on “Creep and Fracture in High Temperature Components—Design and Life Assessment Issues”, London 2005, organized by the European Creep Collaborative Committee.Google Scholar
  16. 16.
    H. THEIL, “Applied Economic Forecasting” (Rand McNally & Company, 1966).Google Scholar

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  1. 1.School of EngineeringUniversity of Wales SwanseaSwanseaUK

Personalised recommendations