Dislocation density and sub-grain size evolution of 2CrMoNiWV during low cycle fatigue at elevated temperatures

T. Mayer, L. Balogh, C. Solenthaler, E. Müller Gubler, S. R. Holdsworth

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

We present the dislocation density and sub-grain size evolution for samples subjected to low cycle fatigue (LCF) loading under various conditions. Interrupted LCF tests have been performed on a cyclic softening bainitic steam turbine rotor steel, 2CrMoNiWV, at total strain amplitudes of ±0.25%, ±0.4% and ±0.7%, strain rates of 0.01 and 0.1% s -1, and temperatures of 500 and 565 °C. Neutron diffraction experiments have been carried out on these samples, which were evaluated by means of a convolutional multiple whole profile peak shape analysis approach. With this analysis, both dislocation density and sub-grain size evolutions have been determined and compared to the results of transmission electron microscopy (TEM) and scanning TEM (STEM) spot-check evaluations. In addition, the proportions of prevailing dislocation types and the correlation factor of the microstructure have been determined. Finally, the results have been used to establish a phenomenological model describing the relationships between the observed cyclic softening and the evolution characteristics of dislocation density and sub-grain size, as a function of strain amplitude, strain rate and temperature.

Original languageEnglish
Pages (from-to)2485-2496
Number of pages12
JournalActa Materialia
Volume60
Issue number6-7
DOIs
Publication statusPublished - Apr 2012

Fingerprint

Strain rate
Fatigue of materials
Transmission electron microscopy
Steel
Steam turbines
Neutron diffraction
Rotors
Temperature
Microstructure
Scanning electron microscopy
Experiments

Keywords

  • Dislocation density
  • Low cycle fatigue
  • Neutron diffraction
  • Sub-grain size
  • TEM

ASJC Scopus subject areas

  • Ceramics and Composites
  • Metals and Alloys
  • Polymers and Plastics
  • Electronic, Optical and Magnetic Materials

Cite this

Dislocation density and sub-grain size evolution of 2CrMoNiWV during low cycle fatigue at elevated temperatures. / Mayer, T.; Balogh, L.; Solenthaler, C.; Müller Gubler, E.; Holdsworth, S. R.

In: Acta Materialia, Vol. 60, No. 6-7, 04.2012, p. 2485-2496.

Research output: Contribution to journalArticle

Mayer, T. ; Balogh, L. ; Solenthaler, C. ; Müller Gubler, E. ; Holdsworth, S. R. / Dislocation density and sub-grain size evolution of 2CrMoNiWV during low cycle fatigue at elevated temperatures. In: Acta Materialia. 2012 ; Vol. 60, No. 6-7. pp. 2485-2496.
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