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Nishi, Hiroshi
Fusion Engineering and Design, 81(1-7), p.269 - 274, 2006/02
Times Cited Count：4 Percentile：30.68(Nuclear Science & Technology)Tensile strength of the diffusion bonded joint was as large as that of Alumina dispersion-strengthened copper (DS Cu), however, the Charpy absorbed energy of the joint was considerably lower than that of DS Cu. Instrumented Charpy impact test and slow-bend Charpy test of diffusion bonded joints were performed to clarify the degradation of Charpy absorbed energy. Elasto-plastic analyses were also carried out in order to study the deformation behavior of the tensile and V-notched specimens for joints. As the results, the fracture behaviors of the impact and slow-bend tests were almost the same. Elasto-plastic analyses showed that the maximum strain occurred at the DS Cu apart from the interface for tensile specimen, however, the strain concentrated at the DS Cu near the interface for the notched specimen. This strain concentration arose from the mechanical heterogeneity between stainless steel and DS Cu in the bonded zone and attributed to the degradation of the absorbed energy of the joints.
Saito, Shigeru; Fukaya, Kiyoshi*; Ishiyama, Shintaro; Amezawa, Hiroo; Yonekawa, Minoru; Takada, Fumiki; Kato, Yoshiaki; Takeda, Takashi; Takahashi, Hiroyuki*; Nakahira, Masataka
Journal of Nuclear Materials, 307-311(Part2), p.1573 - 1577, 2002/12
Times Cited Count：2 Percentile：17.03(Materials Science, Multidisciplinary)no abstracts in English
Yamaoka, Hiroto*; Tsuchiya, Kazuyuki*; Awano, Toshihiko*; Oka, Kiyoshi
Ishikawajima Harima Giho, 42(5), p.260 - 264, 2002/09
no abstracts in English
Saito, Shigeru; Ouchi, Nobuo; Ishiyama, Shintaro; Tsuchiya, Yoshinori*; Nakajima, Hideo; Fukaya, Kiyoshi*
JAERI-Tech 2002-048, 68 Pages, 2002/05
JAERI-Tech-2002-048.pdf:7.86MB
no abstracts in English
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Koizumi, Koichi; Nakahira, Masataka; Takahashi, Hiroyuki*
Fusion Engineering and Design, 58-59, p.869 - 873, 2001/11
Times Cited Count：2 Percentile：19.66(Nuclear Science & Technology)no abstracts in English
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Nakahira, Masataka
Transactions of 16th International Conference on Structural Mechanics in Reactor Technology (SMiRT-16) (CD-ROM), 8 Pages, 2001/08
Fatigue test of the weldments was performed to investigate their fatigue behavior and the effect of the incomplete penetrations on the fatigue strength. Fatigue crack propagation test of their weld metals was also carried out using CT specimen. By calculating stress intensity factors of the weldments contained the incomplete penetrations and cracks using FEM analysis, the fatigue crack propagation rates of weldments were evaluated and compared those of their weld metals. Fatigue life of the weldments was evaluated based on fracture mechanics to discuss the effect of incomplete penetrations on the fatigue strength. As the results, the incomplete penetration behaved as a crack and most of total fatigue life for the weldment was crack propagation life. The crack propagation rates of weldment were in accordance with those of the weld metals. The fatigue strength of the weldment was considerably lower than that of smoothed specimen. The incomplete penetrations affected greatly the fatigue strength of the weldments even if the depth of incomplete penetrations was small.
Saito, Shigeru; Fukaya, Kiyoshi; Ishiyama, Shintaro; Amezawa, Hiroo; Yonekawa, Minoru; Takada, Fumiki; Kato, Yoshiaki; Takeda, Takashi; Takahashi, Hiroyuki*; Koizumi, Koichi
JAERI-Tech 2001-035, 81 Pages, 2001/06
JAERI-Tech-2001-035.pdf:18.91MB
no abstracts in English
Hayashi, Makoto*; Okido, Shinobu*; Morii, Yukio; Minakawa, Nobuaki
Materials Science Research International, Special Technical Publication, 1, p.418 - 423, 2001/05
no abstracts in English
Maki, Akira; ; Taguchi, Katsuya; ; Shimizu, Ryo; Shoji, Kenji;
JNC TN8410 2001-012, 185 Pages, 2001/04
JNC-TN8410-2001-012.pdf:9.61MB
"The third technological meeting of Tokai Reprocessing plant (TRP)" was held in JNFL Rokkasyo site on March 14
, 2001. The technical meetings have been held in the past two times. The first one was about the present status and future plan of the TRP and second one was about safety evaluation work on the TRP. At this time, the meeting focussed on the corrosion experrience, in-service inspection technology and future maintenance plan. The report contains the proceedings, transparancies and questionnaires of the meeting are contained.
Nishi, Hiroshi; Araki, Toshimitsu*
Journal of Nuclear Materials, 283-287(Part.2), p.1234 - 1237, 2000/12
Times Cited Count：17 Percentile：72(Materials Science, Multidisciplinary)no abstracts in English
*;
JNC TN9400 2000-047, 114 Pages, 2000/03
JNC-TN9400-2000-047.pdf:8.25MB
Prediction of weld residual stresses by a general finite element code is beneficial to the improvement of the accuracy of integrity assessment and residual life assessment of FBR plants. This reports develops an evaluation method of weld residual stresses using FINAS. Firstly, we suggested a basic procedure derived from parametric analyses with a simple weld joint model. The procedure can be summarized as follows: (1)For heat conduction analysis, prepare different models corresponding to the number of layers to be modeled. Hand over the analytical results to the following model. (2)Use multi-linear stress-strain curves for modeling the stress-strain response of base metal and weld metal. Use the isotropic hardening rule. (3)When metals are melt, use a user-subroutine to keep stresses from arising. (4)Put the thermal expansion coefficient as zero when heat is being input. Then, using the above procedure and TIG welding, we predicted the weld residual stresses of plate and tube. The results agreed well with the other reports, showing the suggested procedure was reasonable.
Momma, Yoshio*; *; ; ; ; Aoto, Kazumi
JNC TN9400 2000-044, 22 Pages, 2000/03
JNC-TN9400-2000-044.pdf:1.37MB
ln the past the microstructural observation was mostly applied to understand the materials behavior qualitatively in R&D of the new materials and the life prediction for the fast breeder reactor components. However, the correlation between the changes in properties and microstrutures must be clarified to ensure the structural integrity. Particularly we are interested in the method to correlate the long-term properties and microstructural changes at high temperatures. The current research is to quantify the changes in microstructure of the weld metal for the welded structure of the reactor vessel. ln this research we have conducted creep testing of the weld metals at 823 and 873K up to 37,000h. Two types of the weld metals (16Cr-8Ni-2Mo and 18Cr-12Ni-Mo) were subjected to the creep testing. Based on the areas of the precipitates, the microstructural characterization with time and creep damage was attempted. The creep strength of the 16Cr-8Ni-2Mo weld metal is lower than that of the 18Cr-12Ni-Mo one at higher stresses, shorter times. But there is a trend toward to become similar strength with lower stresses and increasing times. The creep-rupture ductility of the 16Cr-8Ni-2Mo weld metal is superior to that of the 18Cr-12Ni-Mo one. The creep-rupture takes place at the interface of the sigma (
) phases precipitated in the delta (
) ferrites at 823K lower stresses and 873K. The amount of precipitates in the 16Cr-8Ni-2Mo weld metal is smaller than that in the 18Cr-12Ni-Mo one at each temperature and stress. Also it is apparent that the amount of the precipitates is primarily responsible to the decomposition of the phase, because the amount of the residual ferrites measured by the Magne-Gauge reduces with times. Using the Larson-Miller parameter it was possible to correlate the amount of the precipitates linearly with the LMP values.
Motooka, Takafumi; Kiuchi, Kiyoshi
JAERI-Research 99-031, 21 Pages, 1999/04
JAERI-Research-99-031.pdf:1.89MB
no abstracts in English
Tachibana, Katsumi; Nishi, Hiroshi; Eto, Motokuni;
JAERI-Tech 99-024, 65 Pages, 1999/03
no abstracts in English
; ; Ishibashi, Yuzo; Takeda, Seiichiro; *; Fujisaku, Kazuhiko*; *
PNC TN8410 98-116, 147 Pages, 1998/08
None
Hoshiya, Taiji; Omi, Masao; Matsui, Yoshinori; *
Journal of Nuclear Materials, 258-263(PT.B), p.2036 - 2040, 1998/00
Times Cited Count：13 Percentile：70.95(Materials Science, Multidisciplinary)no abstracts in English
Aoto, Kazumi; ; ; ; ; Hirakawa, Yasushi
PNC TN9420 97-007, 786 Pages, 1997/06
PNC-TN9420-97-007.pdf:311.86MB
The results of the research on the damaged thermocouple well which caused the sodium leak accident at the outlet of the C-loop intermidiate heat exchanger (IHX) of the secondary heat transfer system of the prototype fast breeder reactor Monju are described in this report. A lot of tests, inspections, observations and measurements were carried out to confirm that the thermocouple well and its attachments to the pipe including welded part are normal by checking the possibility of weld failure or corrosion at the clearance which may cause the damage of the thermocouple well, and to get information of the dimensions relating the estimation of the leaked sodium volume and the leakage path, etc. These tests, etc., were performed for the thermocouple well except the fractured surface, the thermocouple well, the welded parts between the thermocouple well and the attachment, and between the attachment and the outlet pipe, etc., as written below. (1)Accurate measurement of the dimension. (2)Inspection to check the fixing condition between the thermocouple well and the attachment. (3)Measurement of the residual stress. (4)Non destructive testing at some points. (5)Chemical composition analysis. (6)Microscopic observation of metalogical structure at the welded part. (7)Hardness test. (8)Research on corrosion at the clearance. (9)Structure strength test of the thermocouple well. (10)Bending test of the thermocouple's sheath at high temperature.
Watanabe, Katsutoshi; Hamada, Shozo; Kodaira, Tsuneo; Hishinuma, Akimichi
ASM Conference on Welding and Joining Science and Technology, p.615 - 619, 1997/03
no abstracts in English
Watanabe, Katsutoshi; Shindo, Masami; Nakajima, Hajime; Koikegami, Hajime*; Higuchi, Makoto*; Nakanishi, Tsuneo*; Sahira, Kensho*; Marushichi, Koki*; Takeiri, Toshiki*; Saito, Teiichiro*; et al.
JAERI-Research 97-009, 62 Pages, 1997/02
JAERI-Research-97-009.pdf:4.82MB
no abstracts in English
