Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment
The bainitic structure resulting from the austempering of spring steel exhibits high strength and ductility. On the other hand, there appears to be no study on the effects of very high cycle fatigue (VHCF) and ultrasonic nanocrystal surface modification (UNSM) of this bainite structure. Therefore, t...
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The Korean Society of Ocean Engineers
2024-10-01
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| Series: | 한국해양공학회지 |
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| Online Access: | https://doi.org/10.26748/KSOE.2024.058 |
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| author | Seung-Hoon Nahm Min-Soo Suh Chang-Min Suh |
| author_facet | Seung-Hoon Nahm Min-Soo Suh Chang-Min Suh |
| author_sort | Seung-Hoon Nahm |
| collection | DOAJ |
| description | The bainitic structure resulting from the austempering of spring steel exhibits high strength and ductility. On the other hand, there appears to be no study on the effects of very high cycle fatigue (VHCF) and ultrasonic nanocrystal surface modification (UNSM) of this bainite structure. Therefore, this study compared the fatigue properties of VHCF using spring steel with bainitic and martensitic structures and bearing steel data. This study analyzed the characteristics of microstructure transformation associated with the heat treatment cycles and studied and evaluated the fatigue strength characteristics because of the UNSM in terms of fracture mechanics method and fracture surface analysis through electron backscatter diffraction, scanning electron microscopy fracture analysis, and energy-dispersive spectroscopy analysis. The fatigue limit of UNSM-treated spring steel was improved significantly by approximately 33% to 50% compared to the fatigue test results of the untreated material in the VHCF. In the long life range of bainized spring steel, fish-eye cracks appear in the form of the fine granular area, and fatigue cracks occur in the form of fish-eye cracks that occur in the bainite facet and matrix, resulting in a significant increase in fatigue strength and fatigue life. |
| format | Article |
| id | doaj-art-3195ee8b883f453ebdc75789cf2bc3b8 |
| institution | OA Journals |
| issn | 1225-0767 2287-6715 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | The Korean Society of Ocean Engineers |
| record_format | Article |
| series | 한국해양공학회지 |
| spelling | doaj-art-3195ee8b883f453ebdc75789cf2bc3b82025-08-20T01:47:24ZengThe Korean Society of Ocean Engineers한국해양공학회지1225-07672287-67152024-10-0138529430610.26748/KSOE.2024.058Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM TreatmentSeung-Hoon Nahm0https://orcid.org/0000-0002-8929-9269Min-Soo Suh1https://orcid.org/0000-0003-2365-6857Chang-Min Suh2https://orcid.org/0000-0001-7034-8764Korea Research Institute of Standards and ScienceKyoto UniversityKyungpook National UniversityThe bainitic structure resulting from the austempering of spring steel exhibits high strength and ductility. On the other hand, there appears to be no study on the effects of very high cycle fatigue (VHCF) and ultrasonic nanocrystal surface modification (UNSM) of this bainite structure. Therefore, this study compared the fatigue properties of VHCF using spring steel with bainitic and martensitic structures and bearing steel data. This study analyzed the characteristics of microstructure transformation associated with the heat treatment cycles and studied and evaluated the fatigue strength characteristics because of the UNSM in terms of fracture mechanics method and fracture surface analysis through electron backscatter diffraction, scanning electron microscopy fracture analysis, and energy-dispersive spectroscopy analysis. The fatigue limit of UNSM-treated spring steel was improved significantly by approximately 33% to 50% compared to the fatigue test results of the untreated material in the VHCF. In the long life range of bainized spring steel, fish-eye cracks appear in the form of the fine granular area, and fatigue cracks occur in the form of fish-eye cracks that occur in the bainite facet and matrix, resulting in a significant increase in fatigue strength and fatigue life.https://doi.org/10.26748/KSOE.2024.058spring steelbainitemartensiteaustemperingvery high cycle fatigue (vhcf)ultrasonic nanocrystal surface modification (unsm) |
| spellingShingle | Seung-Hoon Nahm Min-Soo Suh Chang-Min Suh Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment 한국해양공학회지 spring steel bainite martensite austempering very high cycle fatigue (vhcf) ultrasonic nanocrystal surface modification (unsm) |
| title | Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment |
| title_full | Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment |
| title_fullStr | Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment |
| title_full_unstemmed | Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment |
| title_short | Variations of VHCF Characteristics by Microstructure of a Spring Steel to UNSM Treatment |
| title_sort | variations of vhcf characteristics by microstructure of a spring steel to unsm treatment |
| topic | spring steel bainite martensite austempering very high cycle fatigue (vhcf) ultrasonic nanocrystal surface modification (unsm) |
| url | https://doi.org/10.26748/KSOE.2024.058 |
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