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Amemiya, Yutaro*; Nakada, Nobuo*; Morooka, Satoshi; Kosaka, Makoto*; Kato, Masaharu*
ISIJ International, 62(2), p.282 - 290, 2022/02
Times Cited Count:3 Percentile:26.37(Metallurgy & Metallurgical Engineering)Amemiya, Yutaro*; Nakada, Nobuo*; Morooka, Satoshi; Kosaka, Makoto*; Kato, Masaharu*
Tetsu To Hagane, 105(2), p.314 - 323, 2019/02
Times Cited Count:5 Percentile:24.55(Metallurgy & Metallurgical Engineering)For deeper understanding of a dynamic accommodation mechanism of internal stress in pearlite originated from the lattice misfit between ferrite and cementite phases, the lattice parameter ratios of cementite were locally analyzed in detail by using the electron backscatter diffraction (EBSD) technique. The EBSD analysis has revealed that lattice parameter ratios of cementite lamellae obviously differ from those of spheroidized cementite particles, which demonstrates that pearlite has a certain amount of internal stress as long as it maintains lamellar structure. The internal stress in pearlite gradually decreased during isothermal holding at 923 K after pearlitic transformation due to interfacial atomic diffusion of iron atoms. However, comparing with theoretical values under Pitsch-Petch orientation relationship, it was understood that large amount of internal stress had been already accommodated upon pearlitic transformation by introduction of misfit dislocations and structural ledges on ferrite/cementite lamellar interfaces. That is, the internal stress of pearlite is dynamically reduced by two different processes; built-in accommodation upon pearlitic transformation and additional time-dependent relaxation after pearlitic transformation. On the other hand, EBSD analysis and neutron diffraction technique gave remarkably different lattice parameters of cementite. From this result, it is concluded that various crystallographic orientation relationships between ferrite and cementite coexist in pearlite. Furthermore, elastic strain energy analysis suggests that the invariant-line criterion on ferrite/cementite interface plays an important role for the selection of orientation relationships in pearlite.
Takeuchi, Ryuji; Kosaka, Hiroshi; Sato, Atsuya*; Tomiyama, Shingo*; Kageyama, Soichiro*; Ikeda, Makoto*
JAEA-Research 2011-008, 77 Pages, 2011/06
Subsurface water balance observation is a kind of methods in order to estimate a recharge rate. Results of the observation are affected by the various factors such as the scale, the topography, a geological feature, the climate. Therefore, the observation in the regional scale is necessary at many basins. The purpose of this study is to confirm the applicability of the method for the evaluation of runoff volume, which is one of parameters to evaluate the recharge rate by surface water balance observation, by geomorphometry and statistical analyses using digital elevation model (DEM). The runoff index which is the original indicator to evaluate the degree of flow rate on a catchment was calculated by the comparison between the result of geomorphometry and statistics analyses, and the observed data of river flow rate in the monitoring stations. Using this index, the flow rate of the Hiyoshi River was evaluated. The evaluated flow rate was about 60% against the observed flow rate.
Kageyama, Soichiro*; Ikeda, Makoto*; Tomiyama, Shingo*; Takeuchi, Ryuji; Kosaka, Hiroshi
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no abstracts in English