Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum
This study aims to produce a cost-effective and low-density, high-strength nanostructured bainitic steel by optimizing the austempering process conditions. To do this, a steel containing 0.8C-1.5Mn-0.6 Cr-0.35Mo-3.5Al was selected and the effects of austempering time and temperature on the microstru...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-03-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785424000541 |
| _version_ | 1797247891256901632 |
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| author | Javad Behzadifar Seyed Mohammad-Ali Boutorabi Hassan Saghafian Larijani |
| author_facet | Javad Behzadifar Seyed Mohammad-Ali Boutorabi Hassan Saghafian Larijani |
| author_sort | Javad Behzadifar |
| collection | DOAJ |
| description | This study aims to produce a cost-effective and low-density, high-strength nanostructured bainitic steel by optimizing the austempering process conditions. To do this, a steel containing 0.8C-1.5Mn-0.6 Cr-0.35Mo-3.5Al was selected and the effects of austempering time and temperature on the microstructure and mechanical properties of this steel were studied. Xrd technique was used to recognize the phases present in the microstructure and measure the retained austenite volume fraction and carbon content. Hardness measurements showed that the highest value was obtained from the specimen containing the highest volume fraction of the bainitic ferrite associated with the retained austenite with the highest carbon content, at the completion time of transformation. Such a combination of microstructure and hardness was applied to find the optimum time at different temperatures during the austempering process. The microstructures of the optimal specimens were evaluated through optical microscopy (OM) and field-emission scanning electron microscopy (FESEM), and the average thickness of the bainitic ferrite plates was calculated. Finally, tensile tests were performed on the optimal specimens to assess the fracture surface through FESEM. For high steel with 3.5 wt% Al, the results indicated that it is possible to obtain a microstructure consisting of bainitic ferrite plates with an average thickness of 53 nm surrounded by the carbon-rich retained austenite with a hardness of 561HV, a yield stress of 1614 MPa, an ultimate tensile strength of 1981 MPa, and a total elongation of 9 %. |
| first_indexed | 2024-03-08T12:52:37Z |
| format | Article |
| id | doaj.art-a94545898b774660b3aa6fd5e00b9ba9 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-04-24T20:05:54Z |
| publishDate | 2024-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-a94545898b774660b3aa6fd5e00b9ba92024-03-24T06:57:10ZengElsevierJournal of Materials Research and Technology2238-78542024-03-0129344352Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminumJavad Behzadifar0Seyed Mohammad-Ali Boutorabi1Hassan Saghafian Larijani2School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran, 1684613114, IranCorresponding author.; School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran, 1684613114, IranSchool of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran, 1684613114, IranThis study aims to produce a cost-effective and low-density, high-strength nanostructured bainitic steel by optimizing the austempering process conditions. To do this, a steel containing 0.8C-1.5Mn-0.6 Cr-0.35Mo-3.5Al was selected and the effects of austempering time and temperature on the microstructure and mechanical properties of this steel were studied. Xrd technique was used to recognize the phases present in the microstructure and measure the retained austenite volume fraction and carbon content. Hardness measurements showed that the highest value was obtained from the specimen containing the highest volume fraction of the bainitic ferrite associated with the retained austenite with the highest carbon content, at the completion time of transformation. Such a combination of microstructure and hardness was applied to find the optimum time at different temperatures during the austempering process. The microstructures of the optimal specimens were evaluated through optical microscopy (OM) and field-emission scanning electron microscopy (FESEM), and the average thickness of the bainitic ferrite plates was calculated. Finally, tensile tests were performed on the optimal specimens to assess the fracture surface through FESEM. For high steel with 3.5 wt% Al, the results indicated that it is possible to obtain a microstructure consisting of bainitic ferrite plates with an average thickness of 53 nm surrounded by the carbon-rich retained austenite with a hardness of 561HV, a yield stress of 1614 MPa, an ultimate tensile strength of 1981 MPa, and a total elongation of 9 %.http://www.sciencedirect.com/science/article/pii/S2238785424000541Nanostructured bainiteAustempering conditionsThe volume fraction of bainitic ferriteThe carbon content of retained austeniteMechanical properties |
| spellingShingle | Javad Behzadifar Seyed Mohammad-Ali Boutorabi Hassan Saghafian Larijani Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum Journal of Materials Research and Technology Nanostructured bainite Austempering conditions The volume fraction of bainitic ferrite The carbon content of retained austenite Mechanical properties |
| title | Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum |
| title_full | Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum |
| title_fullStr | Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum |
| title_full_unstemmed | Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum |
| title_short | Effects of austempering on the microstructure and mechanical properties of high-strength nanostructured bainitic steel containing 3.5 wt% aluminum |
| title_sort | effects of austempering on the microstructure and mechanical properties of high strength nanostructured bainitic steel containing 3 5 wt aluminum |
| topic | Nanostructured bainite Austempering conditions The volume fraction of bainitic ferrite The carbon content of retained austenite Mechanical properties |
| url | http://www.sciencedirect.com/science/article/pii/S2238785424000541 |
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