High resistance to helium embrittlement in reduced activation martensitic steels

A. Kimura, R. Kasada, K. Morishita, R. Sugano, A. Hasegawa, K. Abe, T. Yamamoto, H. Matsui, N. Yoshida, B. D. Wirth, T. D. Rubia

研究成果: Article査読

50 被引用数 (Scopus)


Reduced activation martensitic steels (RAMSs) are the prime candidate structural material for the DEMO reactor and beyond where the material has been considered to suffer severe embrittlement caused by high-dose neutron irradiation and several thousands appm of transmutated helium. However, recent several works show high resistance to helium embrittlement of RAMS. Good performance of RAMS in the presence of rather high concentration of helium is considered to be due to high trapping capacity for helium atoms in the martensitic structure that consists of dislocations, lath boundaries, grain boundaries and carbide/matrix interfaces. To make clear the role of dislocations in trapping helium, thermal helium desorption spectra were measured for iron specimens annealed at different temperatures after cold work. A desorption peak, which increased its height with increasing dislocation density, was observed at around 550 °C, suggesting that dislocations trap helium atoms. A molecular dynamics simulation study for investigating the helium trapping behavior at helium-vacancy complexes suggests that helium is rather strongly bound to the complexes and increases the binding energy of vacancy to the complex, resulting in increasing stability of the complexes at elevated temperatures by reducing thermal emission of vacancies.

ジャーナルJournal of Nuclear Materials
出版ステータスPublished - 2002 12月

ASJC Scopus subject areas

  • 核物理学および高エネルギー物理学
  • 材料科学(全般)
  • 原子力エネルギーおよび原子力工学


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