Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tanigawa, Hiroyasu; Sakasegawa, Hideo*; Hashimoto, Naoyuki*; Zinkle, S. J.*; Klueh, R. L.*; Koyama, Akira*
Fusion Materials Semiannual Progress Report for the Period Ending (DOE/ER-0313/35), p.33 - 36, 2004/04
Extraction replica samples were prepared from F82H-IEA, F82H HT2, JLF-1 and ORNL9Cr to analyze the precipitate distribution. The samples were examined to obtain precipitate size distribution with TEM and to analyze chemical composition distribution with SEM. Back-scattered electron imaging was found to be the effective way to separate Ta-rich precipitate from other precipitates. Results showed that most of the precipitates were M23C6, and the shape is a round ellipsoid in F82H-IEA and HT2, but was a long ellipsoid in JFL-1 and ORNL9Cr. It was also found that MX precipitates were few and large and contain Ti in F82H-IEA and HT2, but a lot of fine MX precipitates without Ti were observed in JLF-1 and ORNL9Cr.
Tanigawa, Hiroyasu; Sakasegawa, Hideo*; Zinkle, S. J.*; Klueh, R. L.*; Koyama, Akira*
Fusion Materials Semiannual Progress Report for the Period Ending (DOE/ER-0313/35), p.30 - 32, 2004/04
Extraction residue was made from several HFIR 11J-irradiated RAFs, and the mass change was measured to investigate the irradiation-enhanced change in precipitation. Two different types of filter with coarse and fine pores were used in order to separate the difference of irradiation effects between larger and smaller precipitates. Unirradiated specimens were examined as well. Results suggest that during irradiation the mass of larger precipitates increased in F82H-IEA, Ni-doped F82H, JLF-1 and ORNL9Cr, fine precipitates disappeared in JLF-1, and fine precipitates increased in Ni-doped F82H.
Tanigawa, Hiroyasu; Sakasegawa, Hideo*; Payzant, E. A.*; Zinkle, S. J.*; Klueh, R. L.*; Koyama, Akira*
Fusion Materials Semiannual Progress Report for the Period Ending (DOE/ER-0313/35), p.37 - 40, 2004/04
XRD analyses were performed on the extraction residue of HFIR 11J-irradiated RAFs to investigate the overall precipitate character. Un-irradiated and aged specimens were examined as well. Results suggested that the distinctive peaks of M23C6 (M; Cr, Fe, W) were observed on all specimens. Peaks possibly related to MX (M;Ta,Ti,V : X ; C, N) were observed on the specimens extracted from un-irradiated JLF-1 and ORNL9Cr, but those peaks were not observed on irradiated specimens.
Hasegawa, Masayuki*; Nagai, Yasuyoshi*; Tang, Z.*; Yubuta, Kunio*; Suzuki, Masahide
JAERI-Tech 2003-015, 137 Pages, 2003/03
JAERI-Tech-2003-015.pdf:9.03MB
no abstracts in English
Uwaba, Tomoyuki; Mizuta, Shunji;
JNC TN9400 2000-028, 41 Pages, 2000/03
JNC-TN9400-2000-028.pdf:2.52MB
14Cr-25Ni optimized advanced austenic steels have been developed to improve the swelling resistance of 15Cr-20Ni austenic stainless steels used for FBR fuel cladding. ln this improvement, Ti,Nb,V and P were dissolved into 14Cr-25Ni marix by means of the high-temperature solution treatment to make finely distributed and stabilized precipitates in the operation. Furthermore, at the final stage of cold-working, cold-working level increased and residual stress was reduced. ln this study, as fablicated microstructure observation, solubility of alloying elements and grain size test in the manufacturing process were evaluated. Following results were obtained. (1)Spherical precipitates were observed in the grain. Most of them were identified as conjugated carbo-nitride [Ti,Nb(C,N)] by EDX analysis. (2)The dissolved percentages of Ti and Ni in the matrix were about 70% and 30% respectively. Undissoved Ti and Nb may react with undissolved carbon and precipitate as MC carbides. (3)High-temperature solution treatment is effective for the sufficient solubility of alloying elements, but it is likely to induce very large grains, which is the cause of defective signal in the ultrasonic alloy testing. The results of the grain size test showed that the large grain size is reduced in low Nb (0.1wt%) alloy compared with the standard alloy (0.2wt%Nb), and the effectiveness for the grain size control by reducing the Nb content was confirmed. Also, it was suggested that the intermediate heat treatment and cold work conditions would possibly avoid the occurrence of the large grain at the final heat treatment.
*; *; *; *
PNC TJ9601 96-003, 38 Pages, 1996/03
In this study, for the purpose of development of a nondestructive detection technique of creep-fatigue damage in Type 316FR stainless steel for fast reactors, application study of electrochemical methods and the Induced Current Potential Drop(ICFPD) was done. Applicability of electrochemical methods to evaluation of grain boundary precipitates which, provide preferred site for cavities was investigated. Anodic polarization curves were measured both in 1N KOH solution and in 1N H
SO
+KSCN solution. An anodic current peak that, corresponds to preferential dissolution of the grain boundary precipitates was observed in the measurements using in the KOH solutlon. It was suggested that evolution of the grain boundary precipitates which should be associated with creep-fatigue damage can be evaluated by the electrochemical method using KOH solution. The results of reactivation ratio of the material in 1N HSO+KSCN solution, which is recognized as the sensitive indicator of Cr-depletion, suggested a correlation between the reactivation ratio and creep-fatigue damage. Clear differences between the as-received material and the creep-fatigue damaged sample were found in ICFPD results. Although more detailed investigation is required to make a conclusion, it was expected that potential drop can reflect creep-fatigue damage in the microstructure, e.g. precipitates cavities, surface cracks. Based on the preliminaly result, the ICFPD technique may be expected to provide a quantitative monitoring capability of creep-fatigue damage.
*; Kurata, Yuji; ; Nakajima, Hajime; Kondo, Tatsuo
Nihon Genshiryoku Gakkai-Shi, 36(10), p.967 - 975, 1994/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
Jitsukawa, Shiro; Hojo, Kiichi; Hishinuma, Akimichi
Journal of Nuclear Materials, 179-181, p.538 - 541, 1991/00
Times Cited Count：2 Percentile：31.89(Materials Science, Multidisciplinary)no abstracts in English
Katano, Y.; ; Katsuta, Hiroji
Journal of Nuclear Materials, 141-143, p.396 - 400, 1986/00
Times Cited Count：2 Percentile：32.47(Materials Science, Multidisciplinary)no abstracts in English
Ueno, Fumiyoshi; Irisawa, Eriko; Seki, Masaharu; Abe, Hitoshi
no journal, ,
no abstracts in English
Iwata, Keiko; Takamizawa, Hisashi; Ha, Yoosung; Okamoto, Yoshihiro; Shimoyama, Iwao; Kojima, Hiroshi*; Mayumi, Ren*; Iwase, Akihiro*; Nagai, Yasuyoshi*; Nishiyama, Yutaka
no journal, ,
Microstructure analysis for thermally aged stainless overlay cladding was conducted by using X-ray absorption. X-ray absorption fine structure analysis was adapted, which was possible to obtain the average information of a material and to identify the bond length and chemical state by the selected atoms. In this study, changes of coordination number and bond length around the Mn atom were recognized.
Shimohashi, Kengo*; Arai, Takahiro*; Ito, Daiyu*; Hirasawa, Izumi*; Miyazaki, Yasunori; Takeuchi, Masayuki
no journal, ,
no abstracts in English
Ouchi, Kazuki; Otobe, Haruyoshi; Kitatsuji, Yoshihiro
no journal, ,
We investigated differences in electrolytic deposition of U and Np. The electrodeposition of Np stopped when the electrode surface was covered with Np(IV) dioxide. This behavior is different from the deposition of U that the reaction continues even if deposits form on the electrode surface. From the result of impedance measurements of deposits, we found that the Np(IV) dioxide on the electrode surface prevent from reducing Np(V) to Np(IV) because of high electrical resistance of Np(IV) dioxide.
Ouchi, Kazuki; Otobe, Haruyoshi; Kitatsuji, Yoshihiro
no journal, ,
We evaluated the electrochemical properties of electrodeposited U(IV) compounds with impedance spectroscopy. After electrolysis was stopped at 1200 s, impedance spectra of U deposits on the electrode surface were measured and confirmed Nyquist plot semicircles originated from U deposits. The spectrum of 4 to 80 minutes after deposition were analyzed based on the equivalent circuit of the electrode covered by the deposits. The obtained electrical resistances were increased with time. This indicates that electrodeposits of U deposits transfer to oxide with high electrical resistance. Transform of chemical species of the U deposits with time could be confirmed from electrochemical properties.
Ouchi, Kazuki; Otobe, Haruyoshi; Kitatsuji, Yoshihiro
no journal, ,
We analyzed electrodeposited U(IV) compounds on the electrode surface with electrochemical impedance spectroscopy. Impedance spectra of U deposits on the electrode surface were observed Nyquist plot semicircles, and these semicircles grew with the increase of deposition amount. This indicates that these semicircles are originated from U deposits. The obtained electrical resistances of U deposits were increased with time. This phenomenon indicates that electrodeposits of U deposits had been transfered into oxide with high electrical resistance.
