MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature
With the emerging significance of creating an acicular ferrite microstructure to provide an optimum set of properties in steel, MnS precipitation behavior on a MnO–SiO2 inclusion at the solid-liquid coexistence temperature was experimentally investigated and thermodynamically elucidated in this stud...
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| Format: | Journal Article |
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Nippon Tekko Kyokai/Iron and Steel Institute of Japan
2020
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| Online Access: | http://hdl.handle.net/20.500.11937/90247 |
| _version_ | 1848765355070062592 |
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| author | Gamutan, Jonah Miki, Takahiro Nagasaka, Tetsuya |
| author_facet | Gamutan, Jonah Miki, Takahiro Nagasaka, Tetsuya |
| author_sort | Gamutan, Jonah |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | With the emerging significance of creating an acicular ferrite microstructure to provide an optimum set of properties in steel, MnS precipitation behavior on a MnO–SiO2 inclusion at the solid-liquid coexistence temperature was experimentally investigated and thermodynamically elucidated in this study. Using a direct method of forming inclusions, alloy samples with varying sulfur concentrations [Fe-1.1Mn-0.10Si-0.05O-S (initial mass%); 0.005 to 0.031 initial mass% S] were prepared by holding at the solid-liquid coexistence temperature for 1 hour.
In samples with less than 0.011 mass% sulfur, the formation of a MnO–SiO2 inclusion with a SiO2-rich precipitate was observed. Formation of SiO2 was described as a consequence of silicon enrichment in the liquid phase, which, under appropriate thermodynamic conditions, homogeneously precipitated and later on coalesced with the primary MnO–SiO2 phase. On the other hand, in samples with more than 0.022 mass% sulfur, heterogeneous precipitation of MnS along the boundary of the primary MnO–SiO2 inclusion and the alloy matrix was observed. Also, the SiO2-rich phase was found to disappear with increasing sulfur addition. Since the likelihood of heterogeneous nucleation is higher than homogeneous nucleation, it was assumed that MnS precipitation on the surface of the primary MnO–SiO2 prevented the secondary SiO2-rich inclusion from coalescing with the existing MnO–SiO2 inclusion. This was also further validated for solute enrichment in the liquid phase, wherein MnS precipitation temperature was found to shift to higher temperatures in alloys with higher sulfur content. |
| first_indexed | 2025-11-14T11:33:56Z |
| format | Journal Article |
| id | curtin-20.500.11937-90247 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:33:56Z |
| publishDate | 2020 |
| publisher | Nippon Tekko Kyokai/Iron and Steel Institute of Japan |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-902472023-02-22T06:57:35Z MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature Gamutan, Jonah Miki, Takahiro Nagasaka, Tetsuya MnS precipitation acicular ferrite solid-liquid coexistence temperature microsegregation With the emerging significance of creating an acicular ferrite microstructure to provide an optimum set of properties in steel, MnS precipitation behavior on a MnO–SiO2 inclusion at the solid-liquid coexistence temperature was experimentally investigated and thermodynamically elucidated in this study. Using a direct method of forming inclusions, alloy samples with varying sulfur concentrations [Fe-1.1Mn-0.10Si-0.05O-S (initial mass%); 0.005 to 0.031 initial mass% S] were prepared by holding at the solid-liquid coexistence temperature for 1 hour. In samples with less than 0.011 mass% sulfur, the formation of a MnO–SiO2 inclusion with a SiO2-rich precipitate was observed. Formation of SiO2 was described as a consequence of silicon enrichment in the liquid phase, which, under appropriate thermodynamic conditions, homogeneously precipitated and later on coalesced with the primary MnO–SiO2 phase. On the other hand, in samples with more than 0.022 mass% sulfur, heterogeneous precipitation of MnS along the boundary of the primary MnO–SiO2 inclusion and the alloy matrix was observed. Also, the SiO2-rich phase was found to disappear with increasing sulfur addition. Since the likelihood of heterogeneous nucleation is higher than homogeneous nucleation, it was assumed that MnS precipitation on the surface of the primary MnO–SiO2 prevented the secondary SiO2-rich inclusion from coalescing with the existing MnO–SiO2 inclusion. This was also further validated for solute enrichment in the liquid phase, wherein MnS precipitation temperature was found to shift to higher temperatures in alloys with higher sulfur content. 2020 Journal Article http://hdl.handle.net/20.500.11937/90247 10.2355/isijinternational.ISIJINT-2019-777 http://creativecommons.org/licenses/by-nc-nd/4.0/ Nippon Tekko Kyokai/Iron and Steel Institute of Japan fulltext |
| spellingShingle | MnS precipitation acicular ferrite solid-liquid coexistence temperature microsegregation Gamutan, Jonah Miki, Takahiro Nagasaka, Tetsuya MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title | MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title_full | MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title_fullStr | MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title_full_unstemmed | MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title_short | MnS Precipitation Behavior in MnO–SiO2 Inclusion in Fe–Mn–Si–O–S Alloy System at Solid-Liquid Coexistence Temperature |
| title_sort | mns precipitation behavior in mno–sio2 inclusion in fe–mn–si–o–s alloy system at solid-liquid coexistence temperature |
| topic | MnS precipitation acicular ferrite solid-liquid coexistence temperature microsegregation |
| url | http://hdl.handle.net/20.500.11937/90247 |