Effects of specimen size on fracture toughness of phosphorous added F82H steels

Byung Jun Kim, Ryuta Kasada, Akihiko Kimura, Hiroyasu Tanigawa

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Reduced-activation ferritic (RAF) steels are promising candidate structural materials for fusion reactor blanket components. However, a large amount of He on grain boundaries over 550-700 appm may cause non-hardening embrittlement (NHE) on the RAF materials. Therefore, understanding the fracture toughness on the RAF steels are critical in design and operation of the reactor. In the present study, constitutive data and widely obtained fracture toughness data sets at transition temperatures of F82H are investigated to establish the master curve method for RAF steels from viewpoints of fracture mechanics. For effective production of irradiation database, small specimen tests is applied to evaluate fracture toughness properties for F82H steels with different levels of phosphorous addition so that it can simulate the effect of fracture mode change from cleavage to intergranular fracture on the shift of transition curve. In this study, effects of specimen size and phosphorous on fracture toughness are also evaluated using the different size specimen (1 CT, 1/2 CT and 1/4 CT). As a result, phosphorous added steels show intergranular fracture in a brittle manner even in temperatures of transition region. The master curve approach is used here for evaluation of fracture toughness change by the degradation of grain boundary strength based on the ASTM E1921.

Original languageEnglish
Pages (from-to)2403-2408
Number of pages6
JournalFusion Engineering and Design
Issue number9-11
Publication statusPublished - 2011 Oct
Externally publishedYes


  • Fracture toughness
  • Intergranular fracture
  • Master curve method
  • Non hardening embrittlement
  • Phosphorus added F82H steels
  • Small specimen test technique

ASJC Scopus subject areas

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


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