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Harjo, S.; Aizawa, Kazuya; Ito, Takayoshi; Arima, Hiroshi; Abe, Jun; Moriai, Atsushi; Sakasai, Kaoru; Nakamura, Tatsuya; Nakatani, Takeshi; Iwahashi, Takaaki; et al.
Materials Science Forum, 652, p.99 - 104, 2010/09
Times Cited Count：21 Percentile：99.37(Materials Science, Characterization & Testing)The construction of The Engineering Materials Diffractometer, TAKUMI of J-PARC has been finished on March 2009, and the commissioning has been started from September 2008 being parallel with the final stage of the construction. In the commissioning, after checking the validity and the stability of the detectors and the data acquisition system, we checked powder diffraction data of a 2 mm diameter of annealed piano wire with combination of beam collimation (high resolution mode), and confirmed that resolution 
/ of less than 0.2% can be achieved. We also reports preliminary results from researches using TAKUMI.
Kiriyama, Koji; Shobu, Takahisa; Shibano, Junichi*; Fujishiro, Tomoyuki; Kaneko, Hiroshi; Miura, Setsuo*
no journal, ,
Shobu, Takahisa; Okazawa, Kazuhiro; Muramatsu, Toshiharu; Takase, Kazuyuki; Tsukimori, Kazuyuki
no journal, ,
Xu, P. G.; Tomota, Yo*; Koo, M.*; Yonemura, Masao*; Suzuki, Tetsuya*; Paradowska, A.*; Zhang, S. Y.*; Adachi, Yoshitaka*
no journal, ,
Deformation induced ferrite transformation related to microstructure refinement has attracted wide attention. However, the in situ crystallographic evolution studies have not been carried out. In this paper, the deformation induced ferrite transformation at two different strain rates was carried out to compare that during isothermal holding without deformation and the effects of hot deformation and strain rate on the dynamic transformation evolution was investigated. The neutron diffraction experiments confirmed that the deformation induced ferrite transformations could appear not only in the austenite region, but also in the austenite-ferrite dual phase region. It was found that the low temperature deformation was more effective than the high temperature to promote the ferrite transformation until a critical strain, and then the accelerating effect was weakened due to the increment of austenite carbon concentration and the appearance of ferrite dynamic recrystallization.
Xu, P. G.; Tomota, Yo*; Li, J.*; Oliver, E. C.*; Adachi, Yoshitaka*
no journal, ,
The dynamic recrystallization evolution of two martensite steels 17Ni-0.2C and 2Mn-0.2C during warm compression were investigated by neutron diffraction. For 17Ni-0.2C, the warm compression at 773K promoted the austenite precipitation from the martensite matrix. The austenite deformation texture gradually increased. For the ferrite, the deformation texture component first increased and then become stable or weak to a certain extent because of the onset of recrystallization texture component. For 2Mn-0.2C, the proper tempering treatment at 873K led to the occurrence of static recovery of martensite to a certain extent and the precipitation of cementite. The onset of ferrite dynamic recrystallization in 2Mn-0.2C was at a higher nominal strain than that in 17Ni-0.2C. It was believed that this difference was mostly related to the different volume fraction of hard second phase.
Shiota, Yoshinori; Tomota, Yo*; Harjo, S.; Kamiyama, Takashi*
no journal, ,
In our previous report on in site neutron diffraction during tensile loading for heavily drawn ferrite and pearlite steels, two points were made clear. One is stress partitioning between the ferrite matrix and the cemente phases for the patented pearlite steel. Another one is the nonlinear elastic deformation above the external stress of 3GPa in the heavily drawn pearlite steel. However, these measurements were performed by the angler dipersion mehteod for {110} planes along the tensile direction, the effect of texture has not been considered. Hence, diffraction from {hkl} planes both in the tensile and transverse directions were observed in this study. Beacuse strong {hkl}
110
fiber formed during severe deformation, the strain behavior was similar to that deformation of {hkl}110 single crystal. As the axis of principal stress is 110 lattice direction, transverse {hkl} deformation in cubic system possessed elastic anisotropy.
Suzuki, Hiroshi; Katsuyama, Jinya; Tobita, Toru; Morii, Yukio
no journal, ,
Residual stress distributions near weld line of an austenitic large scaled butt-welded tube (500 mm diameter, 760 mm length and 28 mm wall thickness) were measured using the neutron diffraction technique. Typical residual stress distributions, which agreed well with some previous works using FEM, were measured in as-welded tube. After machining the slit with the size of 30 mm length, 10 mm depth and 0.5 mm width on the inside wall of the tube, the residual stresses in the axial direction were released in the part of the slit. On the other hand, the residual stress distributions after the repair welding on the outside wall were significantly changed like that tensile residual stresses were observed after the repair welding and compressive stresses were disappeared at all positions in all three directions. In this study, we indicated that the neutron diffraction technique is useful and powerful tool for measuring residual stress distribution in the large scaled mechanical components.
