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DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第2報) : 電子線後方散乱法とデジタル画像相間法を組み合わせたDP鋼の局所ひずみマッピング
Title: | DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第2報) : 電子線後方散乱法とデジタル画像相間法を組み合わせたDP鋼の局所ひずみマッピング |
Other Titles: | Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its’ Microstructure : Part II: Local Strain Mapping of Dual Phase Steel by a Combination Technique of Electron Backscatter Diffraction and Digital Image Correlation Methods |
Authors: | 中田, 伸生1 Browse this author | 池田, 賢一2 Browse this author →KAKEN DB | 首藤, 洋志3 Browse this author | 横井, 龍雄4 Browse this author | 土山, 聡宏5 Browse this author | 波多, 聰6 Browse this author | 中島, 英治7 Browse this author | 高木, 節雄8 Browse this author |
Authors(alt): | Nakada, Nobuo1 | Ikeda, Ken-ichi2 | Shuto, Hiroshi3 | Yokoi, Tatsuo4 | Tsuchiyama, Toshihiro5 | Hata, Satoshi6 | Nakashima, Hideharu7 | Takaki, Setsuo8 |
Keywords: | local strain mapping | heterogeneous strain distribution | electron backscatter diffraction | dual phase steel | digital image correlation |
Issue Date: | May-2016 |
Publisher: | 日本鉄鋼協会 |
Journal Title: | 鉄と鋼 |
Volume: | 102 |
Issue: | 5 |
Start Page: | 253 |
End Page: | 259 |
Publisher DOI: | 10.2355/tetsutohagane.TETSU-2015-086 |
Abstract: | To evaluate heterogeneous strain distribution developed by pre-deformations in dual phase (DP) steel accurately, a combinational technique of Electron Backscatter Diffraction (EBSD) and Digital Image Correlation (DIC) methods was newly introduced in this study. A good correlation is established between kernel average misorientation calculated by EBSD and local equivalent strain measured by DIC in ferrite matrix of DP steels regardless of the difference in deformation process, which means that an EBSD orientation map can be easily converted into an applicative strain map by employing the individual correlation formula. This new technique reveals that very high strain region is locally formed within dozens of micrometer from the punched edge in a punched DP steel. On the other hand, hard martensite grains dispersed in DP steel remarkably promote the heterogeneity of strain distribution in ferrite matrix. As a result, the high strain region is also developed in the form of bands in a cold-rolled DP steel by only 60% thickness reduction at least, as if it is affected by the distribution and morphology of martensite grains. In addition, the local strain mapping demonstrates that the equivalent strain of the high strain band in cold-rolled material is comparable to that of the heavily deformed edge in punched one. The very high strain band in ferrite matrix is characterized by ultrafine grained structure, which leads to the possibility for the losing ductility in ferrite matrix and the martensite cracking. |
Rights: | 著作権は日本鉄鋼協会にある |
Type: | article |
URI: | http://hdl.handle.net/2115/75456 |
Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 池田 賢一
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