Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nakata, Toshiya; Komazaki, Shinichi*; Kono, Yutaka*; Tanigawa, Hiroyasu
Metallurgical Journal, LXIII(Sp.), p.146 - 150, 2010/08
The small punch (SP) test is one method of small specimen test technology. We constructed a model for finite element analysis (FEA) using the Ramberg-Osgood equation to try to estimate tensile properties from the SP test. The results showed that the SP curve obtained from previous experiments could be reproduced by FEA to the point where the necking behavior of SP specimens became prominent. It was found that the relationship between the Mises equivalent stress at the point giving the largest equivalent plastic strain, and the total strain based on the Ramberg-Osgood equation, in the SP specimens, agreed well with the true stress-true strain curve plotted from tensile test measurements, and could thus be used to evaluate the 0.2% proof stress, tensile strength and uniform elongation.
Nakata, Toshiya; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Komazaki, Shinichi*; Fujiwara, Mikio*; Kono, Yutaka*; Koyama, Akira*
Nihon Kinzoku Gakkai-Shi, 71(2), p.239 - 243, 2007/02
Times Cited Count：4 Percentile：33.26(Metallurgy & Metallurgical Engineering)no abstracts in English
Nakata, Toshiya; Komazaki, Shinichi*; Nakajima, Motoki*; Kono, Yutaka*; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Koyama, Akira*
Nihon Kinzoku Gakkai-Shi, 70(8), p.642 - 645, 2006/08
Times Cited Count：4 Percentile：34.16(Metallurgy & Metallurgical Engineering)no abstracts in English
Nakata, Toshiya; Tanigawa, Hiroyasu; Komazaki, Shinichi*; Kono, Yutaka*
no journal, ,
no abstracts in English
Nakata, Toshiya; Tanigawa, Hiroyasu; Ando, Masami; Komazaki, Shinichi*; Kono, Yutaka*
no journal, ,
no abstracts in English
Nakata, Toshiya; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Komazaki, Shinichi*; Kono, Yutaka*; Koyama, Akira*
no journal, ,
no abstracts in English
Nakata, Toshiya; Tanigawa, Hiroyasu; Ando, Masami; Komazaki, Shinichi*; Kono, Yutaka*
no journal, ,
Reduced activation ferritic/martensitic steels are the first candidate material for fusion reactor, and will be used as the structural materials of ITER test blanket modules (TBM). TBM will be assembled by welding various parts, it is important to be clearly mechanical properties of weldments to qualify TBM structure. In this paper, unirradiated mechanical properties of weldments, which is consisted of weld metal, heat affected zone (HAZ) and base metal region, obtained from TIG and EB welded F82H IEA-heat were evaluated by charpy impact and creep test. The creep tests were carried out at temperatures of 773-873 K and at stress levels of 150-260 MPa, with the specimens which include weld metal and HAZ region in the gage section. In these conditions, rupture time of weldments yield to about 100-1000 hours. The mechanism of these properties deterioration will be discussed based on the detailed analyses on microstructure changes.
Tanigawa, Hiroyasu; Nakata, Toshiya*; Kim, D.-H.*; Ando, Masami; Shiba, Kiyoyuki; Hirose, Takanori; Komazaki, Shinichi*; Kono, Yutaka*; Koyama, Akira*
no journal, ,
Reduced activation ferritic/martensitic steels (RAFMs) are recognized as the primary candidate structural materials for fusion blanket systems, as they have been developed based on massive industrial experience of ferritic/martensitic steel replacing Mo and Nb of high chromium heat resistant martensitic steels (such as modified 9Cr-1Mo) with W and Ta, respectively. F82H (Fe-8Cr-2W-V, Ta) is the RAFM which is designed with emphasis on high temperature property and weldablility. Fusion blanket system will be suffer from high temperature/high pressure of its coolant, heat flux of fusion plasma etc., which cause creep and fatigue load on blanket system. On the other hand, the current blanket system design have complicated structure to achieve its function, and require long weld to fabricate its structure. In this paper, unirradiated creep and fatigue properties of base metal and weldments of F82H will be reviewed, and critical issues for design will be discussed.
Nakata, Toshiya; Komazaki, Shinichi*; Kono, Yutaka*; Tanigawa, Hiroyasu
no journal, ,
The small punch (SP) test method has many. However, because of the complex deformation process, it is difficult to evaluate the stress and strain distributions in the SP test specimen. The ability to evaluate material's tensile properties using the SP test would be of great engineering significance. In this research, in order to establish a new procedure for evaluating tensile properties by the SP test, we attempted the stress and strain analyses of the SP test specimen using the finite element method. As the result, the relationship between the maximum von-Mises equivalent stress in the SP specimen and the strain calculated based on the Ramberg-Osgood's law was in good agreement with the true stress-true strain curve obtained from the actual tensile test within uniform elongation. These results indicate that the tensile properties such as yield strength, tensile strength and uniform elongation can be estimated by the SP test and the subsequent finite element analysis.
Komazaki, Shinichi*; Chida, Shinji*; Nakata, Toshiya; Kono, Yutaka*; Tanigawa, Hiroyasu
no journal, ,
no abstracts in English
