Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion
The energy stored in severely deformed ultrafine-grained (UFG) 316L stainless steel was investigated by differential scanning calorimetry (DSC). A sample was processed by high-pressure torsion (HPT) for NÂ =Â 10 turns. In the DSC thermogram, two peaks were observed. The first peak was exothermic and...
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| Format: | Article |
| Language: | English |
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Elsevier
2017-10-01
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| Series: | Journal of Materials Research and Technology |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785417301515 |
| _version_ | 1818509273531940864 |
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| author | Moustafa El-Tahawy Yi Huang Taekyung Um Heeman Choe János L. Lábár Terence G. Langdon JenŠGubicza |
| author_facet | Moustafa El-Tahawy Yi Huang Taekyung Um Heeman Choe János L. Lábár Terence G. Langdon JenŠGubicza |
| author_sort | Moustafa El-Tahawy |
| collection | DOAJ |
| description | The energy stored in severely deformed ultrafine-grained (UFG) 316L stainless steel was investigated by differential scanning calorimetry (DSC). A sample was processed by high-pressure torsion (HPT) for N = 10 turns. In the DSC thermogram, two peaks were observed. The first peak was exothermic and related to the annihilation of vacancies and dislocations. During this recovery, the phase composition and the average grain size were practically unchanged. The energy stored in dislocations was calculated and compared with the heat released in the exothermic DSC peak. The difference was related to the annihilation of vacancy-like defects with a concentration of â¼5.2 Ã 10â4. The second DSC peak was endothermic which was caused by a reversion of αâ²-martensite into γ-austenite, however in this temperature range dislocation annihilation and a moderate grain growth also occurred. The specific energy of the reverse martensitic phase transformation was determined as about â11.7 J/g. Keywords: High-pressure torsion, Stored energy, Stainless steel, Phase transformation, Thermal stability |
| first_indexed | 2024-12-10T22:43:21Z |
| format | Article |
| id | doaj.art-5eeda359e24d452cacda8df493d06fc7 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-12-10T22:43:21Z |
| publishDate | 2017-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-5eeda359e24d452cacda8df493d06fc72022-12-22T01:30:39ZengElsevierJournal of Materials Research and Technology2238-78542017-10-0164339347Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsionMoustafa El-Tahawy0Yi Huang1Taekyung Um2Heeman Choe3János L. Lábár4Terence G. Langdon5JenÅ Gubicza6Department of Materials Physics, Eötvös Loránd University, Budapest, Hungary; Department of Physics, Faculty of Science, Tanta University, Tanta, EgyptMaterials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, United KingdomSchool of Materials Science & Engineering, Kookmin University, Seoul, Republic of KoreaSchool of Materials Science & Engineering, Kookmin University, Seoul, Republic of KoreaDepartment of Materials Physics, Eötvös Loránd University, Budapest, Hungary; Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Budapest, HungaryMaterials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, United KingdomDepartment of Materials Physics, Eötvös Loránd University, Budapest, Hungary; Corresponding author.The energy stored in severely deformed ultrafine-grained (UFG) 316L stainless steel was investigated by differential scanning calorimetry (DSC). A sample was processed by high-pressure torsion (HPT) for N = 10 turns. In the DSC thermogram, two peaks were observed. The first peak was exothermic and related to the annihilation of vacancies and dislocations. During this recovery, the phase composition and the average grain size were practically unchanged. The energy stored in dislocations was calculated and compared with the heat released in the exothermic DSC peak. The difference was related to the annihilation of vacancy-like defects with a concentration of â¼5.2 Ã 10â4. The second DSC peak was endothermic which was caused by a reversion of αâ²-martensite into γ-austenite, however in this temperature range dislocation annihilation and a moderate grain growth also occurred. The specific energy of the reverse martensitic phase transformation was determined as about â11.7 J/g. Keywords: High-pressure torsion, Stored energy, Stainless steel, Phase transformation, Thermal stabilityhttp://www.sciencedirect.com/science/article/pii/S2238785417301515 |
| spellingShingle | Moustafa El-Tahawy Yi Huang Taekyung Um Heeman Choe János L. Lábár Terence G. Langdon JenŠGubicza Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion Journal of Materials Research and Technology |
| title | Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion |
| title_full | Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion |
| title_fullStr | Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion |
| title_full_unstemmed | Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion |
| title_short | Stored energy in ultrafine-grained 316L stainless steel processed by high-pressure torsion |
| title_sort | stored energy in ultrafine grained 316l stainless steel processed by high pressure torsion |
| url | http://www.sciencedirect.com/science/article/pii/S2238785417301515 |
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