Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel
By means of microstructure observation and mechanical property tests, the effects of vacuum graded austempering treatment on carbide precipitation, bainite transformation, hardness and impact toughness of M50 steel were studied. Results show that after the steel was vacuum grading treated at 560 °C...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-11-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785422016301 |
| _version_ | 1811198670988640256 |
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| author | Y. Su P.F. Li S.Y. Wang S. Yang J.D. Wu X.F. Yu H.F. Liu |
| author_facet | Y. Su P.F. Li S.Y. Wang S. Yang J.D. Wu X.F. Yu H.F. Liu |
| author_sort | Y. Su |
| collection | DOAJ |
| description | By means of microstructure observation and mechanical property tests, the effects of vacuum graded austempering treatment on carbide precipitation, bainite transformation, hardness and impact toughness of M50 steel were studied. Results show that after the steel was vacuum grading treated at 560 °C for 10 min, 20 min, 30 min and 60 min and austempered at 200 °C for 2 h, the microstructure is mainly composed of martensite, acicular lower bainite, retained austenite, and carbides (C) in different shapes. With the extension of the grading time from 10 min to 60 min, the content of precipitated carbides after austempering treatment increases from 2.38% to 3.79%, that of the lower bainite increases from 13.14% to 16.03%, and the hardness decreases from 65.06 HRC to 64.26 HRC. After tempering treatment at 550 °C × 2 h for 3 times, the content of precipitated secondary carbides increases from 3.86% to 5.37%, and the hardness of the steel decreases compared to the corresponding austempered steel. Thereinto, the hardness of the tempered steel with the grading time of 20 min is the highest to be 62.92 HRC. After vacuum grading treatment at 560 °C × 10 min, austempering and tempering treatments, the impact toughness of the M50 steel is 16.63 J/cm2, which is enhanced by 50.6% compared to the steel only with vacuum quenching and tempering. This is related to the formation of bainite after graded austempering treatment and the uniform precipitation of fine carbides after tempering. |
| first_indexed | 2024-04-12T01:35:17Z |
| format | Article |
| id | doaj.art-6ff690f5f8164196b9f449bbb19ca4b7 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-04-12T01:35:17Z |
| publishDate | 2022-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-6ff690f5f8164196b9f449bbb19ca4b72022-12-22T03:53:20ZengElsevierJournal of Materials Research and Technology2238-78542022-11-012127212729Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steelY. Su0P.F. Li1S.Y. Wang2S. Yang3J.D. Wu4X.F. Yu5H.F. Liu6School of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, ChinaSchool of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, ChinaSchool of Mechanical Engineering, Shenyang University of Technology, Shenyang, 110870, ChinaSchool of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, ChinaSchool of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, ChinaSchool of Mechanical Engineering, Shenyang University of Technology, Shenyang, 110870, ChinaSchool of Mechanical Engineering, Shenyang University of Technology, Shenyang, 110870, China; Corresponding author.By means of microstructure observation and mechanical property tests, the effects of vacuum graded austempering treatment on carbide precipitation, bainite transformation, hardness and impact toughness of M50 steel were studied. Results show that after the steel was vacuum grading treated at 560 °C for 10 min, 20 min, 30 min and 60 min and austempered at 200 °C for 2 h, the microstructure is mainly composed of martensite, acicular lower bainite, retained austenite, and carbides (C) in different shapes. With the extension of the grading time from 10 min to 60 min, the content of precipitated carbides after austempering treatment increases from 2.38% to 3.79%, that of the lower bainite increases from 13.14% to 16.03%, and the hardness decreases from 65.06 HRC to 64.26 HRC. After tempering treatment at 550 °C × 2 h for 3 times, the content of precipitated secondary carbides increases from 3.86% to 5.37%, and the hardness of the steel decreases compared to the corresponding austempered steel. Thereinto, the hardness of the tempered steel with the grading time of 20 min is the highest to be 62.92 HRC. After vacuum grading treatment at 560 °C × 10 min, austempering and tempering treatments, the impact toughness of the M50 steel is 16.63 J/cm2, which is enhanced by 50.6% compared to the steel only with vacuum quenching and tempering. This is related to the formation of bainite after graded austempering treatment and the uniform precipitation of fine carbides after tempering.http://www.sciencedirect.com/science/article/pii/S2238785422016301M50 steelGrading treatmentAustempering treatmentBainiteCarbides |
| spellingShingle | Y. Su P.F. Li S.Y. Wang S. Yang J.D. Wu X.F. Yu H.F. Liu Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel Journal of Materials Research and Technology M50 steel Grading treatment Austempering treatment Bainite Carbides |
| title | Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel |
| title_full | Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel |
| title_fullStr | Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel |
| title_full_unstemmed | Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel |
| title_short | Influence of vacuum graded austempering treatment on microstructure and mechanical properties of M50 steel |
| title_sort | influence of vacuum graded austempering treatment on microstructure and mechanical properties of m50 steel |
| topic | M50 steel Grading treatment Austempering treatment Bainite Carbides |
| url | http://www.sciencedirect.com/science/article/pii/S2238785422016301 |
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