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Journal of Iron and Steel Research International

, Volume 14, Issue 6, pp 68–73 | Cite as

Microstructure Variation and Hardness Diminution During Low Cycle Fatigue of 55NiCrMoV7 Steel

  • Zhan-ping ZhangEmail author
  • Yu-hong Qi
  • Denis Delagnes
  • Gérard Bernhart
Article

Abstract

The influence of temperature and hardness level on the cyclic behavior of 55NiCrMoV7 steel, and the microstructure variation and hardness diminution during low cycle fatigue behavior were investigated. By means of SEM and XRD, the modality of carbides and the full-width half-maximum (FWHM) of martensite (211) [M(211)] of X-ray diffraction spectrum in fatigue specimen were studied. The results showed that the cyclic stress response behavior generally showed an initial exponential softening for the first few cycles. followed by a gradual softening without cyclic softening saturation. The fatigue behavior of the steel is closely related to the hardness level. The hardness diminution and the variation of half-width M(211) are remarkably influenced by the interaction between the cyclic plastic deformation and the thermal loading when the fatigue temperature exceeds the tempering temperature of the steel.

Keywords

low cycle fatigue 55NiCrMoV7 steel microstructure hardness half-width 

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References

  1. [1]
    Bernhart G, Moulinier G, Brucelle O, et al. High Temperature Low Cycle Fatigue Behaviour of a Martensitic Forging Tool Steel [J]. Int J of Fatigue, 1999, 21(2): 179–186.CrossRefGoogle Scholar
  2. [2]
    Bournicon C. Sollicitations et Modes D’endommagement des Outillages de Forge à Chaud [J]. Traitement Thermique, 1991, 246: 70–77.Google Scholar
  3. [3]
    Delagnes D. Isothermal Fatigue Behaviour and Lifetime of a 5%Cr Hot Work Tool Steel Around the LCF-HCF Transition [D]. Paris, France: EENSMP, 1998.Google Scholar
  4. [4]
    Zhang Z, Delagnes D, Bernhart G. Stress-Strain Behaviour of Tool Steels Under Thermo-Mechanical Loadings: Experiment and Modeling [A]. Franz Jeglitsch, Reinhold Ebner, Harald Leitner, eds. Tool Steels in the Next Century, Proceedings of the 5th International Tooling Conference [C]. Leoben: University of Leoben, 1999. 205–213.Google Scholar
  5. [5]
    Velay V, Bernhart G, Zhang Z, et al. Cyclic Behaviour Modeling of Martensitic Hot Work Tool Steels [A]. Biallas G, Maier HJ, Hahn O, etal, eds. High-Temperature Fatigue, Proceedings CAMP2002 [C]. Bad Lippspringe: Paderborn, 2002. 64–75.Google Scholar
  6. [6]
    Bernhart G, Choi B G, Zhang Z, et al. Single Specimen Methodology for Elasto-Visco-Plastic Fatigue Mode! Identification of Martensitic Steels [A]. Miannay D, Costa P, Francois D, et al, eds. Advances in Mechanical Behaviour, Plasticity and Damage [C]. Oxford: Elsevier, 2000. 1077–1082.Google Scholar
  7. [7]
    Zhang Z, Delagnes D, Bernhart G. Anisothermal Cyclic Plasticity Modelling of Martensitic Steels [J]. Int J of Fatigue, 2002, 24(6): 635–648.CrossRefGoogle Scholar
  8. [8]
    Zhang Z. Anisothermal Cyclic Behaviour Modelling With Taking Account of Tempering Effect of a Martensitic Tool Steel 55NiCrMoV7 [D]. Paris, France: EENSMP, 2002.Google Scholar
  9. [9]
    Zhang Z, Delagnes D, Bernhart G. Tempering Effect on Cyclic Behaviour of a Martensitic Tool Steel [A]. Jens Bergstrom, eds. The Use of Tool Steels: Experience and Research, Proceedings of the 6th International Tooling Conference [C]. Karlstad: Karlstad University, 2002. 573–589.Google Scholar
  10. [10]
    Dong C. PowderX User Manual [M]. Beijing: Institute of Physics, Chinese Academy of Sciences, 1998.Google Scholar

Copyright information

© China Iron and Steel Research Institute Group 2007

Authors and Affiliations

  • Zhan-ping Zhang
    • 1
    Email author
  • Yu-hong Qi
    • 1
  • Denis Delagnes
    • 2
  • Gérard Bernhart
    • 2
  1. 1.Electro-Mechanics and Materials CollegeDalian Maritime UniversityDalian, LiaoningChina
  2. 2.Research Center on Tools, Materials and ProcessesEcole des Mines d’Albi-CarmauxAlbi CT cedex 09France

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