Oxide particle–dislocation interaction in 9Cr-ODS steel

Yuta Ijiri, N. Oono, S. Ukai, S. Ohtsuka, T. Kaito, Yoshitaka Matsukawa

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


Oxide Dispersion Strengthened (ODS) ferritic/martensitic steels have an excellent high temperature strength primarily due to a dislocation pinning effect of nanometric oxide particles. In the present work, the interaction between oxide particles and dislocations in 9CrODS ferritic steel was investigated by both static TEM observation and in-situ TEM observation under dynamic straining conditions. The primary concerns of those observations were the obstacle strength of oxide particles and the type of interactions: attractive or repulsive. In the static observation, the majority (∼90%) of all interaction geometries was characterized as repulsive type. In the in-situ straining experiments, the obstacle strength α of oxide particles was estimated to be no greater than 0.80. The experimentally-determined obstacle strength is smaller than that of Orowan type impenetrable obstacle, whereas those oxide particles are, in theory, ideally strong obstacles. The gap between predicted and measured obstacle strength is attributable to cross-slip motion of screw dislocations on the oxide particles.

Original languageEnglish
Pages (from-to)378-382
Number of pages5
JournalNuclear Materials and Energy
Publication statusPublished - 2016 Dec 1


  • Dislocation-obstacle interaction
  • Dispersion strengthening
  • In-situ TEM straining experiments
  • ODS ferritic steel
  • Obstacle strength
  • Oxide particles

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science (miscellaneous)
  • Nuclear Energy and Engineering


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