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Formation mechanism of coarse columnar γ grains in as-cast hyperperitectic carbon steels
| Title: | Formation mechanism of coarse columnar γ grains in as-cast hyperperitectic carbon steels |
| Authors: | Tsuchiya, S. Browse this author | | Ohno, M. Browse this author | | Matsuura, K. Browse this author | | Isobe, K. Browse this author |
| Keywords: | Casting | | Grain growth | | Columnar austenite grain | | Grain size | | Peritectic solidification |
| Issue Date: | May-2011 |
| Publisher: | Elsevier |
| Journal Title: | Acta Materialia |
| Volume: | 59 |
| Issue: | 9 |
| Start Page: | 3334 |
| End Page: | 3342 |
| Publisher DOI: | 10.1016/j.actamat.2011.02.007 |
| Abstract: | The formation mechanism of as-cast coarse columnar γ grain (CCG) structure in hyperperitectic carbon steels is investigated by means of rapid unidirectional solidification method. This method realizes the cooling conditions similar to those in the vicinity of a practical continuously cast slab surface. The microstructural observation of the quenched samples indicates that the CCG structure develops from the mold side along the direction of the temperature gradient. In the solidifying samples, fine columnar γ grains (FCGs) always exist ahead of the CCG region. Instead of continuous growth into the large grains, the FCGs always shrink and vanish due to the growth of CCGs initially formed near the mold side. Therefore, the grain size at a fixed point of the ingot discontinuously changes from the FCG to the CCG. The validity of this process was supported by numerical analyses. This finding is in marked contrast to the assumption made in conventional grain growth analysis on the CCG structure. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/45645 |
| 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: 大野 宗一
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