Helium ion irradiation effects in ODS and non-ODS ferritic steels

Abstract

Irradiation-resistant materials R&D are one of the key issues to realize fusion power reactor because 14 MeV fusion neutrons will give severe degradation to the structural materials through significant displacement damage with a large amount of transmutation helium up to several thousand appm. When these helium atoms diffuse onto grain boundaries, it can lead to degradation of toughness through intergranular fracture. The present paper describes superior resistance of oxide dispersion strengthened (ODS) ferritic steels to the intergranular fracture due to helium. Dual-beam ion-irradiation technique was applied to reveal the helium effect on the microstructural evolution and mechanical property change of the ODS ferritic steels as well as of the non-ODS ferritic steels. © Springer 2011.