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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
| Title: | 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: | Nakada, Nobuo Browse this author | | Ikeda, Ken-ichi Browse this author →KAKEN DB | | Shuto, Hiroshi Browse this author | | Yokoi, Tatsuo Browse this author | | Tsuchiyama, Toshihiro Browse this author | | Hata, Satoshi Browse this author | | Nakashima, Hideharu Browse this author | | Takaki, Setsuo Browse this author |
| Keywords: | local strain mapping | | dual phase steel | | heterogeneous strain distribution | | electron backscatter diffraction | | digital image correlation |
| Issue Date: | 15-Nov-2016 |
| Publisher: | Iron and Steel Institute of Japan |
| Journal Title: | ISIJ International |
| Volume: | 56 |
| Issue: | 11 |
| Start Page: | 2077 |
| End Page: | 2083 |
| Publisher DOI: | 10.2355/isijinternational.ISIJINT-2016-310 |
| 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 large 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 large 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 large strain band in cold-rolled material is comparable to that of the heavily deformed edge in punched one. The very large 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/2115/75454 |
| 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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