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Tanaka, Keisuke*; Suzuki, Kenji*; Akiniwa, Yoshiaki*; Shobu, Takahisa
Hoshako Ni Yoru Oryoku To Hizumi No Hyoka, 238 Pages, 2009/10
no abstracts in English
Matsumoto, Keisuke*; Shobu, Takahisa; Akiniwa, Yoshiaki*; Yagi, Tsuyoshi*; Yamamoto, Masataka*
Zairyo, 57(7), p.654 - 659, 2008/07
Matsumoto, Keisuke*; Shobu, Takahisa; Akiniwa, Yoshiaki*; Yagi, Tsuyoshi*; Yamamoto, Masataka*
Materials Science Forum, 571-572, p.321 - 326, 2008/00
Shobu, Takahisa; Mizuki, Junichiro; Suzuki, Kenji*; Akiniwa, Yoshiaki*; Tanaka, Keisuke*
JSME International Journal, Series A, 49(3), p.376 - 381, 2006/07
The surface aberration effect in the strain scanning method with a Ge analyzer was examined using high-energy X-rays from the undulator synchrotron source. The use of a Ge (111) analyzer showed remarkable reduction of the surface aberration effect. However, there still existed the surface aberration for the very-near surface region from the surface to the depth of 50 micro meter. A correction method was proposed by taking into account of the effects of the divergence of the Ge analyzer, the mis-setting of the analyzer and the X-ray attenuation. The proposed correction method was very useful for eliminating the surface aberration effect. The correction method enables a high space-resolutive evaluation of the subsurface stress distribution. The method was successfully applied to the determination of the residual stress distribution of the shot-peened steel.
Suzuki, Kenji*; Kawamura, Masashi*; Shobu, Takahisa; Tanaka, Keisuke*; Akiniwa, Yoshiaki*
Zairyo, 55(7), p.634 - 640, 2006/07
no abstracts in English
Shobu, Takahisa; Mizuki, Junichiro; Suzuki, Kenji*; Suzuki, Hiroshi; Akiniwa, Yoshiaki; Tanaka, Keisuke*
Zairyo, 55(7), p.647 - 653, 2006/07
no abstracts in English
SCC device for synchrotron radiation diffraction experiments and application using an austenitic stainless steelYamamoto, Atsushi*; Nakahigashi, Shigeo*; Terasawa, Michitaka*; Mitamura, Toru*; Akiniwa, Yoshiaki*; Yamada, Takayuki*; Liu, L.*; Shobu, Takahisa; Tsubakino, Harushige*
Journal of Synchrotron Radiation, 13(1), p.14 - 18, 2006/01
Times Cited Count：5 Percentile：29.30(Instruments & Instrumentation)Suppressing the stress corrosion cracking (SCC) by reducing the carbon content in austenitic stainless steels is apparently not effective on core shrouds used in boiling water reactors in Japan: trans-granular cracking was found in the shrouds. To clarify the mechanism of the cracking, in situ stress measurements on specimens under stretched conditions in hot water have been attempted in the present study. In situ experiments have been carried out at SPring-8. The SUS316L steel specimen was placed in the in situ device. Sapphire windows were used for the light path in the device. A sufficient diffracted beam intensity was obtained through two sapphire windows and water. The side-inclination method was used for measuring the stress exerted on the specimen. A 2 
sin
plot showed that a tensile stress was induced. The measured stress value is considered to be the summation of stresses owing to pre-straining, in situ loading and residual stress owing to surface grinding.
Shobu, Takahisa; Mizuki, Junichiro; Suzuki, Kenji*; Akiniwa, Yoshiaki*; Tanaka, Keisuke*
Zairyo, 55(1), p.101 - 108, 2006/01
When a gauge volume sank below a specimen surface, the diffraction angle shifts. Thus, it is required to correct the surface aberration. For the annealed specimen of S45C, the shift in the diffraction angle was investigated using a strain scanning method with Ge(111) analyzer. This phenomenon was caused by the difference in the centroid between the geometric and the instrumental gauge volumes. This difference is explained by the following factors; (1)the change in the gauge volume by the divergence of the analyzer, (2)the X-ray penetration depth, (3)the gap of the centre line between the double receiving slits due to mis-setting the analyzer. As a result, the correcting method considered into these factors was proposed. For the shot-peened specimens of S45C, the diffraction angles were measured and corrected by our method. The distribution of the residual stress agreed with that obtained by the removal method.
Shobu, Takahisa; Konishi, Hiroyuki; Mizuki, Junichiro; Suzuki, Kenji*; Suzuki, Hiroshi; Akiniwa, Yoshiaki*; Tanaka, Keisuke*
Materials Science Forum, 524-525, p.691 - 696, 2006/00
The strain scanning method was applied to the evaluation of the subsurface distribution of the residual stress beneath the shot-peened surface of an austenitic stainless steel SUS304L which had coarse grains and preferred orientation. The experiment was performed at beam line BL22XU at SPring-8 using monochromatic X-rays of 70.14 keV and a Ge (111) analyzer. The specimens were annealed or shot-peened and the grain size was about 0.037mm. In order to obtain the diffractions from an enough number of grains, various types of oscillation methods, which were translation, rotation and tilting of the specimen, were examined. The translational oscillation was found to be enough to obtain the accurate strain distribution. By combining the translational oscillation method with the correction to the surface aberration, the subsurface distribution of the residual stress of shot-peened austenitic stainless steel was successfully determined.
Harjo, S.; Moriai, Atsushi; Torii, Shuki; Suzuki, Hiroshi; Suzuya, Kentaro; Morii, Yukio; Arai, Masatoshi; Tomota, Yo*; Akita, Koichi*; Akiniwa, Yoshiaki*
Materials Science Forum, 524-525, p.199 - 204, 2006/00
An engineering diffractometer designed to solve many problems in materials science and engineering including investigations of stresses and crystallographic structures within engineering components is now being developed at J-PARC project. This instrument views a decoupled-poisoned liquid H
moderator, and the primary and the secondary flight paths are 40 m and 2.0 m, respectively, for 90 degree scattering detector banks. The optimization of this instrument has been performed with a Monte Carlo simulation, and an appropriate resolution of less than 0.2 % in 
d/d has been confirmed. A prototyped radial collimator to define a gauge width of 1 mm has been designed and manufactured. From performance tests conducted at the neutron diffractometer for residual stress analysis RESA, the normal distribution with a full width at half maximum of 1.0 mm was obtained in a good agreement with the simulation.
Akiniwa, Yoshiaki*; Tanaka, Keisuke*; Minakawa, Nobuaki; Morii, Yukio
Materials Science Research International, Special Technical Publication, 1, p.427 - 430, 2001/05
no abstracts in English
Minakawa, Nobuaki; Moriai, Atsushi; Saito, Toru; Tanaka, Keisuke*; Akiniwa, Yoshiaki*; Hayashi, Makoto*; Okido, Shinobu*
Nihon Zairyo Gakkai Dai-36-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.263 - 265, 2000/09
no abstracts in English
Akiniwa, Yoshiaki*; Tanaka, Keisuke*; Minakawa, Nobuaki; Morii, Yukio
Proceedings of 6th International Conference on Residual Stressess (ICRS-6), Vol.1, p.25 - 32, 2000/07
no abstracts in English
Akiniwa, Yoshiaki*; Tanaka, Keisuke*; ; Hayashi, Makoto*; Morii, Yukio; Minakawa, Nobuaki
Zairyo, 47(7), p.755 - 761, 1998/07
no abstracts in English
Suzuki, Hiroshi; Machiya, Shutaro; Akiniwa, Yoshiaki; Kasahara, Naoto; Kisohara, Naoyuki
no journal, ,
no abstracts in English
Shobu, Takahisa; Konishi, Hiroyuki; Suzuki, Kenji*; Shibano, Junichi*; Akiniwa, Yoshiaki*; Tanaka, Keisuke*
no journal, ,
no abstracts in English
Suzuki, Hiroshi; Minakawa, Nobuaki*; Akiniwa, Yoshiaki
no journal, ,
The residual stress measurements of surface treated mechanical parts were carried out using neutron diffraction. One is a cross pin with carburizing and the other is a large scale joint pin with high-frequency hardening. The residual stress beneath the surface layer of these samples was quite different. The large tensile residual stress was observed at approximately 4 mm depth from surface in the joint pin, while no higher tensile stress existed in the cross pin.
Suzuki, Hiroshi; Akiniwa, Yoshiaki; Moriai, Atsushi; Morii, Yukio
no journal, ,
no abstracts in English
Shobu, Takahisa; Suzuki, Kenji*; Akiniwa, Yoshiaki*; Tanaka, Keisuke*
no journal, ,
no abstracts in English
Suzuki, Hiroshi; Miyazaki, Takasato*; Kawamura, Hideki*; Akiniwa, Yoshiaki
no journal, ,
no abstracts in English
Harjo, S.; Moriai, Atsushi; Shirakihara, Kaori; Suzuya, Kentaro; Suzuki, Hiroshi; Takata, Shinichi; Morii, Yukio; Arai, Masatoshi; Tomota, Yo*; Akita, Koichi*; et al.
no journal, ,
no abstracts in English
