Mechanism of instability of carbides in Fe-TaC alloy under high energy electron irradiation at 673 K

Hiroaki Abe, Takahiro Ishizaki, Sho Kano, Feng Li, Yuhki Satoh, Hiroyasu Tanigawa, Dai Hamaguchi, Takeshi Nagase, Hidehiro Yasuda

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Reduced activation ferritic/martensitic steels (RAFMs), such as F82H steel, are designed to enhance the high-temperature strength by formation of MX-type nanometer-scale precipitates, mainly TaC. However, their instability under irradiation was recently reported. The purpose of this work, therefore, is to clarify the mechanism employing simultaneous observations under electron irradiation at elevated temperature in a high voltage electron microscope. In this work, Fe-0.2 wt.% TaC was fabricated as a model alloy of F82H steel. The instability of the precipitates was observed under electron irradiation at 1 MeV or above. The remarkable shrinkage and disappearance were clearly observed under irradiation with 1.5 MeV and above. On the contrary, the precipitates were mostly stable below 0.75 MeV. Two kinds of mechanism of the irradiation-induced instability were deduced from the electron-energy dependence. One is the dissolution and diffusion of tantalum from precipitates in ferrite matrix. The other is the displacements of tantalum in precipitates that introduce dissolution of Ta into matrix.

Original languageEnglish
Pages (from-to)695-699
Number of pages5
JournalJournal of Nuclear Materials
Issue number1
Publication statusPublished - 2014 Dec

ASJC Scopus subject areas

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


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