Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Saito, Toru*; Morimoto, Masaaki*; Inagaki, Takashi*; Hong, Y.-S.*; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; et al.
Physics Procedia, 67, p.536 - 542, 2015/07
Times Cited Count:3 Percentile:74.11Japan Atomic Energy Agency (JAEA) has developed the tensile strength prediction method at liquid helium temperature (4K) using the quadratic curve as a function of the content of carbon and nitrogen in order to establish the rationalized quality control of the austenitic stainless steel used in the ITER superconducting coil operating at 4K. ITER is under construction aiming to verify technical demonstration of a nuclear fusion generation. Toroidal Field Coil (TFC), one of superconducting system in ITER, have been started procurement of materials in 2012. JAEA is producing materials for actual product which are the forged materials with shape of rectangle, round bar, asymmetry and etc. JAEA has responsibility to procure all ITER TFC Structures. In this process, JAEA obtained many tensile strength of both room temperature and 4K about these structural materials, for example, JJ1: High manganese stainless steel for structure (0.03C-12Cr-12Ni-10Mn-5Mo- 0.24N) and 316LN: High nitrogen containing stainless steel (0.2Nitrogen). Based on these data, accuracy of 4K strength prediction method for actual TFC Structure materials was evaluated and reported in this study.
Nabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06
Times Cited Count:0 Percentile:0(Engineering, Electrical & Electronic)Iguchi, Masahide; Sakurai, Takeru; Nakahira, Masataka; Koizumi, Norikiyo; Nakajima, Hideo
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
Application of partial penetration welding (PPW) to ITER Toroidal Field Coil structure has been proposed because of limited accessability for weld due to complex geometry and low stress and low importance components. In order to obtain fatigue crack growth (FCG) behavior of PPW joint in cryogenic environment, Japan Atomic Energy Agency performed FCG test at 4K by using Compact Tension (CT) specimens having as-weld notch of PPW. These CT specimens were made from mockups having one of actual joint shape of PPW, double J-groove. As the result of this test, it was observed that crack propagated in weld metal having inclination from as-weld notch. Moreover it was shown that FCG rate of as-weld CT specimens had high FCG rate region in early stage of crack propagation due to residual stress distribution. In addition, application method of this FCG rate to designing of PPW joint was proposed and verified in this study.
Oshikawa, Takumi*; Funakoshi, Yoshihiko*; Imaoka, Hiroshi*; Yoshikawa, Kohei*; Maari, Yasutaka*; Iguchi, Masahide; Sakurai, Takeru; Nakahira, Masataka; Koizumi, Norikiyo; Nakajima, Hideo
Proceedings of 19th International Forgemasters Meeting (IFM 2014), p.254 - 259, 2014/09
ITER is a large-scale experiment that aims to demonstrate that it is possible to produce commercial energy from fusion. ITER Toroidal Field Coil Case (hereinafter referred to as "ITER TFCC") is one of the important components of ITER. The ITER TFCC materials are made of high nitrogen austenitic stainless steel and having various configurations. The ITER TFCC material which manufactured by JCFC has a complex configuration with heaver thickness than other materials. It is difficult to form near net shape to delivery configuration by ordinary open die forging method such as upset and stretching, because the ITER TFCC materials manufactured by JCFC have a complex configuration. Therefore ingot weight and lead time of machining increase when ITER TFCC materials are forged by ordinary open die forging method. Moreover, in order to get good attenuation at Ultrasonic examination, it is necessarily to make fine and uniform grain of the material. However, it is impossible to control grain size of austenitic stainless steel by heat treatment. The grain becomes fine and uniform by only forging process with suitable condition. Therefore, JCFC has studied suitable forging method to become near net shape to delivery configuration and also to get fine grain of center of the material. Based on these result, ITER TFCC materials were manufactured. This innovative forging process led to reduce the weight of ingot compared with general forging. And it had good Ultrasonic attenuation. It was confirmed that the results of material test and nondestructive examination satisfied the requirements of Japan domestic agency (hereinafter referred to as "JADA"). Moreover, the test coupons were taken from center of thick part of product and used for various tests. As the result of tests, it was confirmed that results of material test satisfied the requirements of JADA. It is clear that this innovative forging method is very suitable process for manufacturing of ITER TFCC materials.
Nabara, Yoshihiro; Suwa, Tomone; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; et al.
no journal, ,
no abstracts in English
Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Minemura, Toshiyuki*; Yanagi, Yutaka*; Osemochi, Koichi*
no journal, ,
no abstracts in English
Koizumi, Norikiyo; Nakahira, Masataka; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; Sakurai, Takeru; Takano, Katsutoshi; Yamane, Minoru; Ando, Shinji
no journal, ,
no abstracts in English
Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; Koizumi, Norikiyo
no journal, ,
no abstracts in English
Nabara, Yoshihiro; Suwa, Tomone; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; et al.
no journal, ,
no abstracts in English
Sakurai, Eiko*; Sakurai, Eiichi*; Ishii, Keizo*; Koshio, Shigeki*; Ito, Shun*; Matsuyama, Shigeo*; Koka, Masashi; Yamada, Naoto; Kitamura, Akane; Sato, Takahiro; et al.
no journal, ,
no abstracts in English
Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Morimoto, Masaaki; Inagaki, Takashi; Tanaka, Nobuhiko; Hong, Y.-S.*; Koizumi, Norikiyo
no journal, ,
no abstracts in English
Iguchi, Masahide; Sakurai, Takeru; Morimoto, Masaaki*; Hong, Y.-S.*; Inagaki, Takashi; Tanaka, Nobuhiko; Nakahira, Masataka; Hemmi, Tsutomu; Matsui, Kunihiro; Koizumi, Norikiyo
no journal, ,
no abstracts in English
Sakurai, Takeru; Iguchi, Masahide; Saito, Toru; Nakahira, Masataka
no journal, ,
no abstracts in English
Nabara, Yoshihiro; Suwa, Tomone; Ozeki, Hidemasa; Sakurai, Takeru; Kajitani, Hideki; Iguchi, Masahide; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; et al.
no journal, ,
no abstracts in English
Nabara, Yoshihiro; Suwa, Tomone; Ozeki, Hidemasa; Sakurai, Takeru; Kajitani, Hideki; Iguchi, Masahide; Hemmi, Tsutomu; Shimono, Mitsugu; Ebisawa, Noboru; Sato, Minoru; et al.
no journal, ,
no abstracts in English
Iguchi, Masahide; Sakurai, Takeru; Inagaki, Takashi; Tanaka, Nobuhiko; Hwang, S.*; Ino, Masanobu; Nakahira, Masataka; Hemmi, Tsutomu; Matsui, Kunihiro; Koizumi, Norikiyo
no journal, ,
no abstracts in English