Degradation of tungsten monoblock divertor under cyclic high heat flux loading

Shuhei Nogami, Michitoshi Toyota, Wenhai Guan, Akira Hasegawa, Yoshio Ueda

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

The degradation behavior of the ITER divertor under the cyclic high heat flux loading has been varied in the previous studies, which would be induced by the intrinsic difference in the thermo-mechanical properties of each pure W material. Therefore, the experimental characterization of the thermo-mechanical properties of the W materials and the numerical structural analysis using these data are necessary to clarify the degradation mechanism and the prediction of the fracture scenario and lifetime. In this study, the degradation behavior of the pure W monoblock divertor mockup during the cyclic high heat flux loading test at 20 MW/m2 was evaluated and the macro-crack formation mechanism was discussed based on the structural analysis. The macro-crack formation of the divertor mockup in the present study could occur due to a complexed low temperature cleavage fracture accompanied by the plastic deformation under cyclic loading. The fatigue, especially the low temperature fatigue with plastic deformation, could be a mechanism factor for the macro-crack formation. However, further study considering the thermo-mechanical fatigue and the effect of the low temperature plastic deformation is necessary to quantitatively evaluate the macro-crack formation mechanism by the fatigue.

Original languageEnglish
Pages (from-to)49-60
Number of pages12
JournalFusion Engineering and Design
Volume120
DOIs
Publication statusPublished - 2017 Jul

Keywords

  • Crack
  • Cyclic high heat flux loading
  • Divertor
  • Fatigue life
  • Finite element analysis
  • Ratchet deformation
  • Recrystallization
  • Strength
  • Tungsten

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

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