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CMiyazawa, Takeshi; Kikuchi, Yuta*; Ando, Masami*; Yu, J.-H.*; Yabuuchi, Kiyohiro*; Nozawa, Takashi*; Tanigawa, Hiroyasu*; Nogami, Shuhei*; Hasegawa, Akira*
Journal of Nuclear Materials, 575, p.154239_1 - 154239_11, 2023/03
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)Yabuuchi, Kiyohiro*; Suzudo, Tomoaki
Journal of Nuclear Materials, 574, p.154161_1 - 154161_6, 2023/02
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)In nuclear materials, irradiation defects cause degradation of mechanical properties. In these materials, the relationship between dislocations and voids is particularly important for mechanical strength. Although only spherical voids have been studied in the past, this study focuses on faceted voids, which are observed simultaneously with spherical voids. In the current study, molecular dynamics was used to analyze the effect of faceted voids in the irradiation hardening of pure iron. Specifically, we clarified the difference in obstacle strength and interaction processes between spherical voids and faceted voids, and that even faceted voids show differences in interaction depending on their crystallographic arrangement with dislocations.
Yabuuchi, Kiyohiro*; Kimura, Akihiko*; Suzudo, Tomoaki
no journal, ,
Irradiation of high-energy particles into materials induces the formation of various lattice defects, which significantly influence their mechanical properties. Voids, which are aggregates of vacancies, are among such defects and become obstacles causing materials hardening. So far, we have been investigating obstacle strength factor of the facet voids created by ion-beam irradiation to pure Fe crystals. Because some ambiguity of the experimentally-measured factor was observed, we suspect that positional relation between interacting voids and dislocations influence the factor. The current study aimed at numerically investigating how this positional relation influences the factor by using molecular dynamics.
Suzudo, Tomoaki; Yabuuchi, Kiyohiro*
no journal, ,
We conducted a series of numerical studies for the fusion materials degradation by using the Helios computer system. We used the first principles method for grain boundary segregation/embrittlement of bcc iron and rhenium/osmium migration in tungsten, and molecular dynamics methods were used for the modeling of material hardening due to phase separation and void nucleation in steels.
Kimura, Akihiko*; Yuzawa, Sho*; Yabuuchi, Kiyohiro*; Sakamoto, Kan*; Hirai, Mutsumi*; Ukai, Shigeharu*; Yamashita, Shinichiro; Kusagaya, Kazuyuki*
no journal, ,
no abstracts in English
Yuzawa, Sho*; Yabuuchi, Kiyohiro*; Kimura, Akihiko*; Sakamoto, Kan*; Hirai, Mutsumi*; Yamashita, Shinichiro
no journal, ,
Oxide dispersion strengthened steel with high Cr and Al concentration in chemical composition (FeCrAl-ODS steel) has been proposed as a promising candidate for the accident tolerant fuel cladding of light water reactors (LWRs) because of their excellent oxidation and corrosion resistance under high temperature water and steam environments. Neither there are no sufficient knowledge on welding technology of FeCrAl-ODS nor it is known that aluminum addition remarkably degrades the weldability of the ODS steel. In this study, electron beam (EB) welding and tungsten inert gas (TIG) welding were applied to the SUS430 endcap welding to cladding tube made of FeCrAl-ODS steel and performed the bonding strength and corresponding damage structure evaluations at the bonding part.
Kimura, Akihiko*; Yabuuchi, Kiyohiro*; Sakamoto, Kan*; Yamashita, Shinichiro; Kusagaya, Kazuyuki*
no journal, ,
The joining technique of FeCrAl-ODS stainless steel is considered to be the indispensable technology in the development of the accident tolerant fuel cladding for LWRs. In this study, the strength of end cap joining part welded by the conventional EB weld was measured and X-ray CT checks were performed to the end cap joining part to obtain the relationship between the strength and the microstructure. The end cap welding condition was considered from the obtained results.
Hamasato, Tsunehiko*; Matsukawa, Yoshitaka*; Tsujimura, Soyo*; Sakaguchi, Chisato*; Tsurekawa, Sadahiro*; Homma, Yoshiya*; Yabuuchi, Kiyohiro*; Yamaguchi, Masatake
no journal, ,
no abstracts in English
