Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures
Single-phase bcc-ferrite in an interstitial free (IF) steel was deformed to different strains in a wide range from low to high strains (ε = 1–7) by torsion under different Zener-Hollomon (Z) conditions. The specimens were rapidly quenched after the torsion to preserve microstructures formed under di...
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| Format: | Article |
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KeAi Communications Co., Ltd.
2020-03-01
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| Series: | Nano Materials Science |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589965120300076 |
| _version_ | 1818537555639926784 |
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| author | Reza Gholizadeh Daisuke Terada Akinobu Shibata Nobuhiro Tsuji |
| author_facet | Reza Gholizadeh Daisuke Terada Akinobu Shibata Nobuhiro Tsuji |
| author_sort | Reza Gholizadeh |
| collection | DOAJ |
| description | Single-phase bcc-ferrite in an interstitial free (IF) steel was deformed to different strains in a wide range from low to high strains (ε = 1–7) by torsion under different Zener-Hollomon (Z) conditions. The specimens were rapidly quenched after the torsion to preserve microstructures formed under different deformation conditions. The results showed that during high-Z (low-temperature) deformation, grains were subdivided by geometrically necessary boundaries (GNBs) via the grain subdivision mechanism. Deformation to high strains (ε > 5) led to the ultrafine lamellar structures (with grain sizes < 1 μm) mainly composed of GNBs having high misorientation angles. Decreasing Z with increasing temperature and/or decreasing strain rate accelerated thermally activated processes, such as dynamic recovery and boundary migration. Unlike the ultrafine lamella formed under the high-Z condition, a variety of microstructures having equiaxed morphologies with fine to coarse grain sizes (>1 μm) were realized with decreasing Z. The significance of the grain subdivision and the thermally activated phenomena on the formation of various microstructures under different deformation conditions is discussed. |
| first_indexed | 2024-12-11T18:52:16Z |
| format | Article |
| id | doaj.art-4f5665e6e8e94c08b72817ac0cb48d79 |
| institution | Directory Open Access Journal |
| issn | 2589-9651 |
| language | English |
| last_indexed | 2024-12-11T18:52:16Z |
| publishDate | 2020-03-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Nano Materials Science |
| spelling | doaj.art-4f5665e6e8e94c08b72817ac0cb48d792022-12-22T00:54:16ZengKeAi Communications Co., Ltd.Nano Materials Science2589-96512020-03-01218395Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperaturesReza Gholizadeh0Daisuke Terada1Akinobu Shibata2Nobuhiro Tsuji3Department of Materials Science and Engineering, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan; Corresponding author.ESISM (Elements Strategy Initiative for Structural Materials), Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan; Department of Advanced Materials Science and Engineering, Chiba Institute of Technology, Tsudanuma, Narashino, 275-0016, JapanDepartment of Materials Science and Engineering, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan; ESISM (Elements Strategy Initiative for Structural Materials), Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, JapanDepartment of Materials Science and Engineering, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan; ESISM (Elements Strategy Initiative for Structural Materials), Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, JapanSingle-phase bcc-ferrite in an interstitial free (IF) steel was deformed to different strains in a wide range from low to high strains (ε = 1–7) by torsion under different Zener-Hollomon (Z) conditions. The specimens were rapidly quenched after the torsion to preserve microstructures formed under different deformation conditions. The results showed that during high-Z (low-temperature) deformation, grains were subdivided by geometrically necessary boundaries (GNBs) via the grain subdivision mechanism. Deformation to high strains (ε > 5) led to the ultrafine lamellar structures (with grain sizes < 1 μm) mainly composed of GNBs having high misorientation angles. Decreasing Z with increasing temperature and/or decreasing strain rate accelerated thermally activated processes, such as dynamic recovery and boundary migration. Unlike the ultrafine lamella formed under the high-Z condition, a variety of microstructures having equiaxed morphologies with fine to coarse grain sizes (>1 μm) were realized with decreasing Z. The significance of the grain subdivision and the thermally activated phenomena on the formation of various microstructures under different deformation conditions is discussed.http://www.sciencedirect.com/science/article/pii/S2589965120300076Severe plastic deformationGrain subdivisionUltrafine grainsZener-Hollomon parameterBoundary migrationElectron backscattering diffraction (EBSD) |
| spellingShingle | Reza Gholizadeh Daisuke Terada Akinobu Shibata Nobuhiro Tsuji Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures Nano Materials Science Severe plastic deformation Grain subdivision Ultrafine grains Zener-Hollomon parameter Boundary migration Electron backscattering diffraction (EBSD) |
| title | Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures |
| title_full | Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures |
| title_fullStr | Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures |
| title_full_unstemmed | Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures |
| title_short | Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures |
| title_sort | strain dependence of deformation microstructures in ultra low c if steel deformed to high strains by torsion at elevated temperatures |
| topic | Severe plastic deformation Grain subdivision Ultrafine grains Zener-Hollomon parameter Boundary migration Electron backscattering diffraction (EBSD) |
| url | http://www.sciencedirect.com/science/article/pii/S2589965120300076 |
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