Journal of Materials Science

, Volume 43, Issue 6, pp 1910–1913 | Cite as

Static fracture toughness of ultra-fine grained steels processed by thermo-mechanical warm rolling

  • Hai QiuEmail author
  • Keitaro Enami
  • Kazuo Hiraoka
  • Kotobu Nagai
  • Yukito Hagihara


Ultra-fine grained steels were recently developed by thermo-mechanical warm rolling. Their low-temperature fracture toughness was evaluated in terms of crack tip opening displacement (CTOD) in this paper. Effect of temperature on CTOD and the correlation between CTOD and grain size were investigated, and the experimental results showed that refining ferrite grains can increase the fracture toughness of steel and lower the sensitivity of fracture toughness to temperature. The fracture toughness of the developed ultra-fine grained steels was superior to that of hot-rolled steel SM490B with similar chemical composition.


Ferrite Fracture Toughness Pearlite Cementite Particle Charpy Impact Test 


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Hai Qiu
    • 1
  • Keitaro Enami
    • 1
  • Kazuo Hiraoka
    • 1
  • Kotobu Nagai
    • 1
  • Yukito Hagihara
    • 2
  1. 1.Materials Reliability CenterNational Institute for Materials ScienceTsukubaJapan
  2. 2.Faculty of Science and TechnologySophia UniversityTokyoJapan

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