A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel
A new combination of factors enhancing the stabilization of austenite, including pre-existed austenite among quenched martensite, prior deformation, and partitioning at high temperatures is employed to create a multi-component refined microstructure in a medium Mn steel (Fe–4Mn–0.31C–2Ni–0.5Al–0.2Mo...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-11-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785421010619 |
| _version_ | 1818969316946608128 |
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| author | Saeed Sadeghpour Mahesh C. Somani Jukka Kömi L. Pentti Karjalainen |
| author_facet | Saeed Sadeghpour Mahesh C. Somani Jukka Kömi L. Pentti Karjalainen |
| author_sort | Saeed Sadeghpour |
| collection | DOAJ |
| description | A new combination of factors enhancing the stabilization of austenite, including pre-existed austenite among quenched martensite, prior deformation, and partitioning at high temperatures is employed to create a multi-component refined microstructure in a medium Mn steel (Fe–4Mn–0.31C–2Ni–0.5Al–0.2Mo, wt.%). The microstructure evolution and phase fraction during the processing are systematically investigated using various characterization methods. The microstructure of the specimen after 0.4 strain deformation of 73% martensite–27% austenite at 250 °C and subsequent partition-annealing at 600 °C for 20 min was composed of several phases including tempered martensite, fresh martensite, pearlite, 10% of retained austenite (RA) and undissolved cementite. By increasing the annealing temperature, the pearlitic transformation was suppressed, whereas recrystallization of the deformed martensite and carbide dissolution occurred following annealing at 650 °C for 20 min resulting in an ultrafine-grained microstructure composed of equiaxed ferrite, 32% RA along with some fresh martensite during final cooling and few carbide precipitates. The results demonstrate that the combinatorial approach accelerated partitioning of alloying elements from martensite and carbides to largely pre-existing austenite is responsible for the improved austenite stabilization during intercritical annealing of the deformed dual-phase specimens. However, competitive processes are also enhanced so that the RA content is not increased by deformation. |
| first_indexed | 2024-12-20T14:18:39Z |
| format | Article |
| id | doaj.art-17e59338213943488f8869464c5dd1c4 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-12-20T14:18:39Z |
| publishDate | 2021-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-17e59338213943488f8869464c5dd1c42022-12-21T19:37:59ZengElsevierJournal of Materials Research and Technology2238-78542021-11-011534263446A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steelSaeed Sadeghpour0Mahesh C. Somani1Jukka Kömi2L. Pentti Karjalainen3Corresponding author.; Centre for Advanced Steels Research, University of Oulu, 90014 Oulu, FinlandCentre for Advanced Steels Research, University of Oulu, 90014 Oulu, FinlandCentre for Advanced Steels Research, University of Oulu, 90014 Oulu, FinlandCentre for Advanced Steels Research, University of Oulu, 90014 Oulu, FinlandA new combination of factors enhancing the stabilization of austenite, including pre-existed austenite among quenched martensite, prior deformation, and partitioning at high temperatures is employed to create a multi-component refined microstructure in a medium Mn steel (Fe–4Mn–0.31C–2Ni–0.5Al–0.2Mo, wt.%). The microstructure evolution and phase fraction during the processing are systematically investigated using various characterization methods. The microstructure of the specimen after 0.4 strain deformation of 73% martensite–27% austenite at 250 °C and subsequent partition-annealing at 600 °C for 20 min was composed of several phases including tempered martensite, fresh martensite, pearlite, 10% of retained austenite (RA) and undissolved cementite. By increasing the annealing temperature, the pearlitic transformation was suppressed, whereas recrystallization of the deformed martensite and carbide dissolution occurred following annealing at 650 °C for 20 min resulting in an ultrafine-grained microstructure composed of equiaxed ferrite, 32% RA along with some fresh martensite during final cooling and few carbide precipitates. The results demonstrate that the combinatorial approach accelerated partitioning of alloying elements from martensite and carbides to largely pre-existing austenite is responsible for the improved austenite stabilization during intercritical annealing of the deformed dual-phase specimens. However, competitive processes are also enhanced so that the RA content is not increased by deformation.http://www.sciencedirect.com/science/article/pii/S2238785421010619Medium Mn steelRetained austeniteStabilityPartitioningDeformationAnnealing |
| spellingShingle | Saeed Sadeghpour Mahesh C. Somani Jukka Kömi L. Pentti Karjalainen A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel Journal of Materials Research and Technology Medium Mn steel Retained austenite Stability Partitioning Deformation Annealing |
| title | A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel |
| title_full | A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel |
| title_fullStr | A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel |
| title_full_unstemmed | A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel |
| title_short | A new combinatorial processing route to achieve an ultrafine-grained, multiphase microstructure in a medium Mn steel |
| title_sort | new combinatorial processing route to achieve an ultrafine grained multiphase microstructure in a medium mn steel |
| topic | Medium Mn steel Retained austenite Stability Partitioning Deformation Annealing |
| url | http://www.sciencedirect.com/science/article/pii/S2238785421010619 |
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