Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments
EUROFER97 steel plates for nuclear fusion applications are usually manufactured by hot rolling and subsequent heat treatments: (1) austenitization at 980 °C for 30 min, (2) rapid cooling and (3) tempering at 760 °C for 90 min. An extended experimental campaign was carried out with the scope of impro...
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MDPI AG
2021-11-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/22/10598 |
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| author | Giulia Stornelli Andrea Di Schino Silvia Mancini Roberto Montanari Claudio Testani Alessandra Varone |
| author_facet | Giulia Stornelli Andrea Di Schino Silvia Mancini Roberto Montanari Claudio Testani Alessandra Varone |
| author_sort | Giulia Stornelli |
| collection | DOAJ |
| description | EUROFER97 steel plates for nuclear fusion applications are usually manufactured by hot rolling and subsequent heat treatments: (1) austenitization at 980 °C for 30 min, (2) rapid cooling and (3) tempering at 760 °C for 90 min. An extended experimental campaign was carried out with the scope of improving the strength of the steel without a loss of ductility. Forty groups of samples were prepared by combining cold rolling with five cold reduction ratios (20, 40, 50, 60 and 80%) and heat treatments at eight different temperatures in the range 400–750 °C (steps of 50 °C). This work reports preliminary results regarding the microstructure and mechanical properties of all the cold-rolled samples and the effects of heat treatments on the samples deformed with the greater CR ratio (80%). The strength of deformed samples decreased as heat treatment temperature increased and the change was more pronounced in the samples cold-rolled with greater CR ratios. After heat treatments at temperature up to 600 °C yield stress (YS) and ultimate tensile strength (UTS) of samples deformed with CR ratio of 80% were significantly larger than those of standard EUROFER97 but ductility was lower. On the contrary, the treatment at 650 °C produced a fully recrystallized structure with sub-micrometric grains which guarantees higher strength and comparable ductility. The work demonstrated that EUROFER97 steel can be strengthened without compromising its ductility; the most effective process parameters will be identified by completing the analyses on all the prepared samples. |
| first_indexed | 2024-03-10T05:44:39Z |
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| id | doaj.art-e8f3e8d6b5944b35b3584fda58e0e5c2 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T05:44:39Z |
| publishDate | 2021-11-01 |
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| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-e8f3e8d6b5944b35b3584fda58e0e5c22023-11-22T22:16:06ZengMDPI AGApplied Sciences2076-34172021-11-0111221059810.3390/app112210598Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical TreatmentsGiulia Stornelli0Andrea Di Schino1Silvia Mancini2Roberto Montanari3Claudio Testani4Alessandra Varone5Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, 00133 Rome, ItalyDipartimento di Ingegneria, Università di Perugia, Via G. Duranti 93, 06125 Perugia, ItalyRINA Consulting Centro Sviluppo Materiali, Via di Castel Romano 100, 00128 Rome, ItalyDipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, 00133 Rome, ItalyCALEF-ENEA CR-Casaccia, Via Anguillarese 301, S. Maria di Galeria, 00123 Rome, ItalyDipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, 00133 Rome, ItalyEUROFER97 steel plates for nuclear fusion applications are usually manufactured by hot rolling and subsequent heat treatments: (1) austenitization at 980 °C for 30 min, (2) rapid cooling and (3) tempering at 760 °C for 90 min. An extended experimental campaign was carried out with the scope of improving the strength of the steel without a loss of ductility. Forty groups of samples were prepared by combining cold rolling with five cold reduction ratios (20, 40, 50, 60 and 80%) and heat treatments at eight different temperatures in the range 400–750 °C (steps of 50 °C). This work reports preliminary results regarding the microstructure and mechanical properties of all the cold-rolled samples and the effects of heat treatments on the samples deformed with the greater CR ratio (80%). The strength of deformed samples decreased as heat treatment temperature increased and the change was more pronounced in the samples cold-rolled with greater CR ratios. After heat treatments at temperature up to 600 °C yield stress (YS) and ultimate tensile strength (UTS) of samples deformed with CR ratio of 80% were significantly larger than those of standard EUROFER97 but ductility was lower. On the contrary, the treatment at 650 °C produced a fully recrystallized structure with sub-micrometric grains which guarantees higher strength and comparable ductility. The work demonstrated that EUROFER97 steel can be strengthened without compromising its ductility; the most effective process parameters will be identified by completing the analyses on all the prepared samples.https://www.mdpi.com/2076-3417/11/22/10598EUROFER97RAFM steelsthermo-mechanical treatmentsmicrostructuredislocation densityrecrystallization |
| spellingShingle | Giulia Stornelli Andrea Di Schino Silvia Mancini Roberto Montanari Claudio Testani Alessandra Varone Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments Applied Sciences EUROFER97 RAFM steels thermo-mechanical treatments microstructure dislocation density recrystallization |
| title | Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments |
| title_full | Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments |
| title_fullStr | Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments |
| title_full_unstemmed | Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments |
| title_short | Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments |
| title_sort | grain refinement and improved mechanical properties of eurofer97 by thermo mechanical treatments |
| topic | EUROFER97 RAFM steels thermo-mechanical treatments microstructure dislocation density recrystallization |
| url | https://www.mdpi.com/2076-3417/11/22/10598 |
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