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Kanayama, Hideyuki; Hiyoshi, Noritake*; Ito, Takamoto*; Ogawa, Fumio*; Wakai, Takashi
Zairyo, 66(2), p.86 - 92, 2017/02
This study presents creep characteristics of Mod. 9Cr-1Mo steel with various sized specimens and environment. Creep tests were performed using three different sizes of specimen and three different type of testing environment. Specimens are a bulk specimen which has 6mm diameter and 30mm gage length, a miniature specimen which has 2mm diameter and 10mm gage length and a thin plate specimen which has 0.76mm thickness, 1.5mm width and 7.62mm gage length. Three different type of testing environment are air, 99.99% Ar gas and vacuum. In the same environmental condition, there was no effect of specimen size on time to rupture. Time to rupture of Mod. 9Cr-1Mo steel in Ar gas was shorter than that in air and vacuum. Oxide thickness is not dominant factor in time to rupture. Fracture mode at specimen surface in Ar gas might be dominant factor in shorter time to rupture. Effect of specimen size and environment on creep strength of Mod. 9Cr-1Mo steel was evaluated on the basis of thinning.
Ishijima, Yasuhiro; Ueno, Fumiyoshi
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 4 Pages, 2015/05
In this study, to evaluate the effect of thermal aging on creep properties of Alloy 625, we carried out creep tests on aged and solution-treated Alloy 625 at 1073 K. According to the creep test results, time-to-rupture decreased by thermal aging when test stress was more than 100 MPa, but did not change when test stress was less than 100 MPa for any specimens. In the solution-treated alloy, creep deformation behaviors changed over 100 MPa. These results show that time-to-rupture was constant because intermetallic compounds precipitated when the test stress was less than 100 MPa in solution-treated alloy. The observed relationship between creep strain rate and test time showed that the precipitation started after 100 hr for solution treated alloys. These results suggest that intermetallic compounds precipitate immediately after furnace operation. And it is appropriate to use creep data of thermal-aged Alloy 625 for the reducing roasting furnace lifetime prediction.
Uwaba, Tomoyuki
JNC TN9420 2000-005, 28 Pages, 2000/03
JNC-TN9420-2000-005.pdf:0.94MB
In the first phase of the feasibility study, their basic objectives are presentating the feasible image and scenario of development of the FBR cycle system, which is composed of the fast reactor, spent fuel reprocessing and fuel manufacturing facility. In the development of the FBR system in this phase, various ideas of plants are to be studied, which include coolant types such as sodium, heavy metals, gases(CO
, He), wator, and middle or small size of the reactor, and fuel types (MOX, metal and nitride). In this report, as a part of this study, materials used for the core of the helium gas cooled reactor and their integrity (corrosion, mechanical and irradiation property) under high temperature helium atmosphere were investigated from open literatures.
Tsuji, Hirokazu
Nihon Genshiryoku Gakkai-Shi, 41(4), p.383 - 384, 1999/04
no abstracts in English
Kaji, Yoshiyuki; Tsuji, Hirokazu; Sakino, Takao*; Fujita, Mitsutane*; Kinugawa, Junichi*; Tachi, Yoshiaki*; Saito, Junichi*; Kano, Shigeki*; Shimura, Kazuki*; Nakajima, Ritsuko*; et al.
JAERI-Tech 99-007, 32 Pages, 1999/02
no abstracts in English
Takeda, Tetsuaki; Iwatsuki, Jin*; Inagaki, Yoshiyuki; Ogawa, Masuro
Proceedings of 7th International Conference on Nuclear Engineering (ICONE-7) (CD-ROM), 10 Pages, 1999/00
no abstracts in English
Takeda, Tetsuaki; Iwatsuki, Jin*; Inagaki, Yoshiyuki; Ogawa, Masuro
JAERI-Tech 98-044, 34 Pages, 1998/11
no abstracts in English
Saito, Junichi; Morinaga, Masahiko*; Kano, Shigeki
PNC TN9410 98-072, 97 Pages, 1998/07
Research on structural materials which will be utilized even in the severe environment of high-temperature liquid alkali metals has been promoted in order to develop the frontiers of materials techniques. The super-heat resisting alloys which are based on refractory metals, Nb and Mo, are aimed as promising materials used in such an environment. The corrosion resistance in liquid Li and the mechanical properties such as creep and tensile strengths at high temperatures are important for these structural materials. On the basis of many expeliments and analyses of these properties at 1473K, the material design of Nb-based and Mo-based alloys has-been carried out successfully. In this report, all the previous experimental results of corrosion tests in liquid Li were summarized systematically for Nb-based and Mo-based alloys. The corrosion mechanism was proposed on the basis of a series of analyses, in particular, focussing on the deposition mechanism of corrosion products on the surface and also on the initiation and growth mechanism of cracks on the corroded surface of Nb-based alloys. The principal results are as follows. (1)For the deposition mechanism, a reaction took place first between dissolved metallic elements and nitrogen which existed as an impurity in liquid Li and then corrosion products (nitrides) precipitated on the metal surface. Subsequently, another reaction took place between dissolved metalic elements in liquid Li, and corrosion products (intermetallic compounds) precipitated on the metal surface. The composition of deposited corrosion products could be predicted on the basis of the deposition mechanism. (2)For the crack initiation mechanism, the chemical potential diagrams were utilized in order to understand the formation of Li-M-O ternary oxides which caused cracks to be formed on the corroded surface. Consequently, it was evident that not only the concentration of the dissolved oxygen in the alloy but also the concentration of Li which ...
Morinaga, Masahiko*; *; *
PNC TJ9603 98-002, 48 Pages, 1998/03
[PURPOSE]Both the Nb-based and Mo-based alloys have been designed and developed in order to establish the frontier technique for super-heat-resisting materials used in the liquid alkali metal environment at high temperatures. In this study, mechanical properties of the designed Nb-1Hf alloy were experimentally evaluated. In addition, the brittleness of Nb-based alloys observed at 1073K were discussed. Moreover, characteristics of both the designed Nb-based and the Mo-based alloys were summarized in a consistent way. [EXPERIMENTAL METHODS] (1)Tensile test : The tensile test was performed at room temperature and 1473K in an Ar gas atmosphere for the designed Nb-1Hf alloy and also for commercial Nb-1Zr alloy. (2)High temperature creep test:The creep test of the designed Nb-1Hf alloy was carried out at 1473K in an Ar gas atmosphere under several applied stress levels. (3)TEM observation : The TEM observation was performed with the creep specimens tested at both 1073K and 1273K in order to get information for the 1073K brittleness of the Nb-1Zr alloy. [RESULTS AND DISCUSSIONS] (1)Tensile test : The tensile stress and the proof stress of the designed Nb-1Hf alloy were slightly lower than those of commercial Nb-1Zr alloy at room tempetarure. But the alloy was superior in the elongation to the Nb-1Zr alloy. High temperature tensile properties were not able to be evaluated properly because of the large grain size of the specimens. (2)High temperature creep test : The Nb-1Hf alloy was superior in the ereep resistance to other solid solution hardened Nb-based alloys. (3)TEM observation : A modulated structure with about 1nm preiod was observed in the specimen which was brittle at 1073K. This was supposed to cause the 1073K brittleness of the Nb-1Zr alloy. [CONCLUSION] The tensile strength of the designed Nb-1Hf alloy was slightly lower at room temperature than that of the commercial Nb-1Zr alloy. But, the designed alloy was superior in high temperature creep properties to any
Tachibana, Katsumi; Nishi, Hiroshi; Eto, Motokuni;
JAERI-Tech 98-010, 107 Pages, 1998/03
no abstracts in English
Watanabe, Kazuo
Hyojun Busshitsu; Bunseki, Keisoku No Shinraisei Kakuho No Tameni, p.175 - 178, 1998/00
no abstracts in English
Tsuji, Hirokazu; ; Fujita, Mitsutane*; Kano, Shigeki*; Tachi, Yoshiaki*; Shimura, Kazuki*; Nakajima, Ritsuko*; Iwata, Shuichi*
Materials for Advanced Power Engineering 1998, p.1739 - 1745, 1998/00
no abstracts in English
Takeda, Tetsuaki; Iwatsuki, Jin*; Ogawa, Masuro
Nihon Kikai Gakkai Dai-6-Kai Doryoku, Enerugi Gijutsu Shimpojiumu '98 Koen Rombunshu, p.90 - 95, 1998/00
no abstracts in English
Morinaga, Masahiko*; *; *; *
PNC TJ9603 97-001, 95 Pages, 1997/03
[PURPOSE] Nb-based and Mo-basd alloys have been investigated in order to develop the frontiers of matelials technique which will be utililized in the environment of high-temperature liquid alkali metals. In this study, both mechanical properties and corrosion resistance to liquid Li were evaluated for two designed Mo-based alloys, Mo-15Re-0.1Zr and Mo-15Re-0.1Zr-0.1Ti. In addition, a series of corrosion test was performed with provisionally designed Nb-based alloys, Nb-(1-4)Hf. [EXPERIMENTAL METHODS] (1)High-temperature tensile test : A tensile test in the Ar atmosphere was carried out at 1473K for the designed Mo-based alloys. Commercial TZM alloy was also tested as a reference. (2)High-temperature creep test : A Creep test in the Ar atmosphere was performed at 1473K under the several applied stress levels for the designed Mo-based alloys. (3)Workability test : A three-point bend test was carried out at room temperature to evaluate the workability of the designed Mo-based alloys. (4)Corrosion resistance to liquid Li : Both the provisionally desingned Nb-based alloys and the designed Mo-based alloys were immersed in the liquid Li at 1473K. The weight change was measured as an indication of the corrosion resistance. Also, the Auger electron spectroscopy analysis was performed with several specimens to examine the surface state of them after corrosion tests. [RESULTS AND DISCUSSIONS] (1)High-temperature tensile properties : The designed Mo-based alloys were superior in the tensile properties at 1473K to the commercial TZM alloy. In fact, both the tensile and yield strengths of them were about 1.5 and 2.3 times higher than the TZM alloy, respectively. (2)High-temperature creep properties : The creep rate of the designed Mo-based alloys at 1473K was lower, compared to other solid solution hardening Mo-based alloys, but higher than the precipitation hardening TZM alloy. (3)Workability : The workability of the designed Mo-based alloys was satisfactory regardless ...
; Shindo, Masami
JAERI-Tech 96-051, 18 Pages, 1996/11
no abstracts in English
Tsuji, Hirokazu; *; *; Nakajima, Hajime; Shindo, Masami
JAERI-Conf 96-010, 0, p.385 - 399, 1996/07
no abstracts in English
Morinaga, Masahiko*; *; *; *; Inoue, Satoshi*
PNC TJ9603 96-001, 79 Pages, 1996/03
[PURPOSE] In order to develop the frontier domain of technique for the high temperature liquid alkali metal, candidate Nb-based and Mo-based alloys are needed. They are needed to have excellent compatibility with liquid Li (max. 1200
C) and super-heat-resistance. In this study, alloy design using a d-electrons alloy theory and estimation of designed alloy were performed. [EXPERIMENTAL METHODS] (1)Workability : A bend test was carried out with the provisionally designed Mo-based alloys, but by modifying the compositions by adding intergranular strengthening elements, Ti, B, C, Hf, into them to improve the ductility. (2)Corrosion resistance to liquid Li : The provisionally desingned Nb-based alloys were immersed in liquid Li at 1200C for three hundred hours, and the weight change due to the corrosion was measured. The corrosion surface was also analyzed using SEM and EPMA. In addition, a similar corrosion test was carried out with binary Nb-based and Mo-based alloys. (3)Embrittlement at 800C : A series of experiments such as the hardness test, X-ray analysis and microstructure observation was perfomed with the Nb-1Zr alloy which was creep-tested at 800C or 1200C. Also, a Nb-1Zr alloy specimen which was not creep-tested, was used as a reference specimen. [RESULTS AND DISCUSSIONS] (1)Workability : The Ti addition into the Mo-based alloys was effective in improving workability. The brittleness of Mo may be caused by the existence of oxygen in the grain boundaries, so that the formation of Ti oxides probably weakened the oxygen effect, resulting in the better workability of the alloy. However, B, C and Hf additions into Mo-based alloys never improved the workability. (2)Corrosion resistance to liquid Li : Many cracks were observed on the corroded surface of the provisionally designed Nb-based alloys despite the addition of a corrosion resistant element, Hf, into them. In paticular, such cracks were developed ...
Watanabe, Kazuo
Bunseki, 0(3), p.196 - 197, 1996/00
no abstracts in English
Morinaga, Masahiko*; Saito, Junichi*; Murata, Yoshinori*; Kano, Shigeki; *; Tachi, Yoshiaki; Inoue, Satoshi*
PNC TY9623 95-001, 165 Pages, 1995/03
None
Tsuji, Hirokazu; *; *; Nakajima, Hajime
Journal of Nuclear Science and Technology, 31(4), p.274 - 278, 1994/04
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
