著者

池田 義雅 高村 正人 箱山 智之 大竹 淑恵 熊谷 正芳 鈴木 裕士

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

pp.TETSU-2017-080, (Released:2018-02-05)

参考文献数

17

被引用文献数

8

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Neutron engineering diffraction is a powerful technique which provides the information of the micro structure of steels in bulk-average, while X-ray diffraction or Electron backscatter diffraction can provide information only from the surface layer. However, such measurement using neutron diffraction is typically performed in a large facility such as a reactor and a synchrotron, while a compact neutron source has never been used for this purpose. Authors have recently developed a neutron diffractometer installed in Riken Accelerator driven compact Neutron Source (RANS) and succeeded in the measurement of texture evolution of a steel sheet. In this study, we made an attempt to measure the volume fraction of retained austenite by RANS. Background noise was carefully eliminated in order to detect as many diffraction peaks as possible with low flux neutrons. The volume fraction was estimated by Rietveld analysis. The accuracy of the measurement result was discussed by comparing with those obtained by a large neutron facility (J-PARC TAKUMI). The volume fraction obtained by RANS with reasonable measurement time, i.e. 30-300 min, showed only 1-2% discrepancies with those obtained in J-PARC. These comparisons suggest that neutron diffraction by RANS is capable of quantitative analysis of the volume fraction of crystal phases, showing the possibility of practical use of an in-house compact neutron source in the industry.

著者

箱山 智之 桑原 利彦

出版者

日本学術会議 「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」

雑誌

理論応用力学講演会 講演論文集 第61回理論応用力学講演会

巻号頁・発行日

pp.111, 2012 (Released:2012-03-28)

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金属板材から円管試験片を製作し,サーボ制御円管バルジ試験機を用いて,軸力と内圧を負荷することにより,線形応力経路における大ひずみ塑性変形特性を測定する試験方法を考案した.本試験方法を590MPa級高張力鋼板に適用し,二軸引張応力下での塑性変形特性を詳細に測定すると同時に,最適な降伏関数の同定を行った.その結果以下の知見を得た.(1)590MPa級高張力鋼板において相当塑性ひずみ換算で16%までの等塑性仕事面の測定ができ,最大主ひずみ0.24までの応力-ひずみ曲線の測定に成功した.(2) 次数6又は次数8のYld2000降伏関数が本供試材の変形挙動を概ね良く再現できることがわかった.実験値の再現精度をさらに向上させるためには,異方硬化の定式化が必要と考える.