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Li, Y.; Momma, Yoshio*; Hongo, Hiromichi*; Tabuchi, Masaaki*
Journal of Nuclear Materials, 405(1), p.44 - 49, 2010/10
Times Cited Count:8 Percentile:49.36(Materials Science, Multidisciplinary)Obara, Satoshi; Wakai, Takashi; Asayama, Tai; Yamada, Yoshiyuki*; Nakazawa, Takanori*; Yamazaki, Masayoshi*; Hongo, Hiromichi*
Tetsu To Hagane, 96(4), p.172 - 181, 2010/04
This paper describes the effect of heat treatment on mechanical properties of 9Cr-W-Mo-V-Nb steel as a part of development of high Cr steel for fast breeder reactor (FBR). The effects of normalizing temperature and tempering temperature and time on creep properties were investigated from the viewpoint of microstructures. Creep strength increased with increase in normalizing temperature from 950C to 1200C. The microstructural factors that improve creep strength are increased amount of MX which precipitated during tempering process and increased dislocation density. In addition, coarsening of prior austenite grain size also contribute to increasing creep strength. Although creep rupture time of 780C-1h tempering specimen was greater than that of 700C-1h and 750C-1h tempering specimen in a long-term region exceeding 20000h at 650C, creep ductility and reduction of area of the former remarkably degraded compared to those of the latter.
Obara, Satoshi; Yamada, Yoshiyuki*; Nakazawa, Takanori*; Yamazaki, Masayoshi*; Hongo, Hiromichi*
no journal, ,
no abstracts in English
Miyashita, Yuta*; Nakazawa, Takanori*; Obara, Satoshi; Yamazaki, Masayoshi*; Hongo, Hiromichi*
no journal, ,
no abstracts in English
Obara, Satoshi; Wakai, Takashi; Asayama, Tai; Yamada, Yoshiyuki*; Nakazawa, Takanori*; Yamazaki, Masayoshi*; Hongo, Hiromichi*
no journal, ,
no abstracts in English
Obara, Satoshi; Wakai, Takashi; Asayama, Tai; Yamada, Yoshiyuki*; Nakazawa, Takanori*; Yamazaki, Masayoshi*; Hongo, Hiromichi*
no journal, ,
This paper describes the effect of heat treatment on long-term creep properties of 9Cr-W-Mo-V-Nb steel which in the specification of ASME Grade 92 as a part of development of high Cr steel for fast breeder reactor (FBR). The effects of normalizing temperature and tempering temperature and time on long-term creep properties were investigated from the viewpoint of microstructures.
Yamamoto, Kenji*; Yamashita, Hayato; Onizawa, Takashi; Kimura, Kazuhiro*; Sawada, Kota*; Hongo, Hiromichi*
no journal, ,
316FR steel is a candidate material for the main components of the fast reactor, and its design allowable stress is specified in Japan Society of Mechanical Engineers fast reactor standard. The reactor will be larger in size. For the design, welding is also required at a part to be a high-temperature and high-stress. Therefore, allowable stress for the weld joint is required. In the evaluation of welded joints, it is necessary to consider the characteristics of the weld metal and heat affected zone in addition to the base material. In this paper, by comparing the strength properties of 316FR steel base metal and weld joint, it was examined whether it is necessary to specify the allowable stress of the weld joint in the restriction of the primary stress of the JSME fast reactor standard.