Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kurata, Yuji; Abe, Yuji*; Futakawa, Masatoshi; Oigawa, Hiroyuki
no journal, ,
Liquid lead-bismuth is a candidate material used for accelerator driven systems and fast reactors. Oxygen control in liquid lead-bismuth is essential in this system and oxygen sensors are the critical instruments for the active oxygen control system. In this study a regeneration treatment was investigated for the oxygen sensor which had become showed incorrect electromotive force between liquid lead-bismuth and a reference electrode due to some degradation. The Pt/air probe based on yttria-stabilized zirconia solid electrolyte was tested. It was shown that the oxygen sensor with incorrect outputs was be able to become a correct sensor indicating theoretical values above about 400
C after a regeneration treatment.
Yamaguchi, Masatake; Ebihara, Kenichi; Suzudo, Tomoaki; Itakura, Mitsuhiro; Kaburaki, Hideo
no journal, ,
no abstracts in English
Saito, Junichi; Ara, Kuniaki; Fukunaga, Koichi*; Oka, Nobuki*; Nagai, Masahiko*
no journal, ,
no abstracts in English
Kim, S.-W.; Otsuka, Satoshi; Kaito, Takeji; Inoue, Masaki
no journal, ,
no abstracts in English
Otsuka, Satoshi; Kaito, Takeji; Kim, S.-W.; Inoue, Masaki; Asayama, Tai; Suzuki, Junichi; Onuma, Masato*
no journal, ,
With a view to making clear the correlation between microstructure and high-temperature strength of 9Cr-ODS ferritic/martensitic duplex steel, the correlation between matrix ferrite proportion and high-temperature strength was quantitatively evaluated. The evaluated results were compared to the nano-structure data such as oxide particle diameter and number density evaluated in the companion report. Both the decreasing excess oxygen and the increasing titanium provides for enhancement of ferrite proportion, which is accompanied by the increasing number density of nano-scale oxide particles, thus appreciably improving high-temperature creep strength. This result is consistent with the previous TEM observation results showing that nano-scale oxide particles are more densely dispersed in ferrite than in tempered-martensite. The increase of ferrite proportion is shown to certainly improve high-temperature creep strength even though the number density of nano-scale oxide particles is kept constant.
Onuma, Masato*; Suzuki, Junichi; Otsuka, Satoshi; Kaito, Takeji; Kim, S.-W.; Inoue, Masaki; Asayama, Tai
no journal, ,
This study discussed the interrelation between chemical composition and nano-scale oxide particle dispersion of the 9Cr-ODS steel for fast reactor fuel cladding application using small angle scattering (SAS) analysis, which is viewed as a strong tool for quantitative evaluation of nano-structure such as particle diameter and number density. Decreasing excess oxygen as well as increasing titanium is shown to provide the considerable increase of nano-scale particle population as well as the reduction of particle diameter. The type of these particles are identified to be Y
TiO
and the number density is evaluated to be in the range between 1E17 and 1E19 (cm
). The elevation of hot-extrusion temperature from 1150 C to 1200 C reduced 20% of nano-scale oxide particle number density.
Abe, Yosuke; Jitsukawa, Shiro
no journal, ,
During ageing, Cu precipitates were observed initially coherent and on further growth they begin to transform by the sequence of bcc-9R-3R-fcc. Since structures of Cu precipitates are considered to be relevant to embrittlement, it is important to understand the mechanisms and conditions of precipitate transformation. In this work we investigate the dependency of the size of Cu precipitate and vacancy concentration on the structures of the precipitate by using the combination of the simulated annealing and molecular dynamics method. We firstly demonstrated that the phase transformation to 9R takes place in diameter of 5-6 nm for pure-Cu precipitate. Moreover, for the precipitate with a vacancy concentration 5at.%, the phase transformation can occur even in 4-5 nm assisted by the diffusional contribution of vacancies and nucleation of fcc embryos by them. This precipitate size that the phase transformation starts to occur is in good agreement with the experimentally observed one.
Murayama, Yuki*; Nagata, Shinji*; Tsuchiya, Bun*; Shikama, Tatsuo*; Inoue, Aichi; Yamamoto, Shunya
no journal, ,
no abstracts in English
Koseki, Shinji*; Nagata, Shinji*; Tsuchiya, Bun*; Shikama, Tatsuo*; Yamamoto, Shunya; Inoue, Aichi
no journal, ,
no abstracts in English
Yamamoto, Masahiro*; Hayashi, Shigenari*; Ukai, Shigeharu*; Kaito, Takeji; Otsuka, Satoshi
no journal, ,
JAEA has found out and proved that high-temperature strength of 9Cr-ODS steel is considerably improved by the formation of residual-alpha ferrite/martensite duplex microstructure. This study discussed the mechanism on residual-alpha ferrite formation using thermo-dynamic model.
Numata, Hiroya*; Hayashi, Shigenari*; Ukai, Shigeharu*; Otsuka, Satoshi; Kaito, Takeji
no journal, ,
This study discussed the recrystallization mechanism from cold-worked texture in 12Cr-ODS ferritic steel.
Chikada, Nobuyoshi*; Hayashi, Shigenari*; Ukai, Shigeharu*; Otsuka, Satoshi; Kaito, Takeji
no journal, ,
It may be possible that the high-temperature strength of 9Cr-ODS ferritic/martensitic steel is largely improved by the formation of ultra-fine residual-alpha phase. This study discussed the correlation between ultra-fine residual-alpha formation and mechanical strength in ODS ferritic steel.
Kimura, Akihiko*; Kasada, Ryuta*; Kishimoto, Hirotatsu*; Iwata, Noriyuki*; Zhang, C.*; Isselin, J.*; Muthukumar, N.*; Inoue, Masaki; Okuda, Takanari*; Abe, Fujio*; et al.
no journal, ,
The project named as "Super ODS Steel Research and Development towards Highly Efficient Nuclear Systems" will be reviewed.
Inoue, Aichi; Yamamoto, Shunya; Nagata, Shinji*; Tsuchiya, Bun*; Shikama, Tatsuo*
no journal, ,
no abstracts in English
Takeyama, Akinori; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
Silicon carbide (SiC) films as a hydrogen separation membrane were prepared using a novel preparation technique. The films were obtained by a coating of precursor films on porous alumina supports followed by an immersion into cycohexane, curing in an inert atmosphere and pyrolisis. A selectivity of the film, which is defined as the ratio of the amount of hydrogen (H) to nitrogen (N) which passed thorough the membrane, was increased up to 6.1 as increasing the immersion time. This is supposed that precursor in pores is dissolved by cyclohexane and pores are filled with the precursor solution, which leads to a decrease of the pore diameter and an improvement of the selectivity.
Onitsuka, Takashi; Ando, Masami; Jitsukawa, Shiro; Iwai, Takeo*
no journal, ,
no abstracts in English
Ono, Masao; Hao, T.; Iguchi, Yusuke*; Esaka, Fumitaka; Okayasu, Satoru; Mashimo, Tsutomu
no journal, ,
no abstracts in English
-Co thin filmsSakai, Seiji; Matsumoto, Yoshihiro; Sugai, Isamu*; Mitani, Seiji*; Takanashi, Koki; Takagi, Yasumasa*; Nakagawa, Takeshi*; Yokoyama, Toshihiko*; Shimada, Toshihiro*; Maeda, Yoshihito
no journal, ,
no abstracts in English