| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Mechanism behind the creation of ultrafine grains at machined surface of 0.45% carbon steel during high-speed turning process |
| Author(s) |
Hyung-Won Park, Masaki Matsuda, Kanji Ishitaka, Shinichi Funase, Atsushi Tomizawa, Akira Hosokawa, Jun Yanagimoto, Takashi Ueda |
| On-Site Speaker (Planned) |
Hyung-Won Park |
| Abstract Scope |
The high-speed turning of 0.45% carbon steel using an Al2O3 tool at speeds ranging from 64 to 923 m/min was studied to assess the cutting behavior (temperature, force, and chip formation) and ultrafine grain development at machined surfaces. Stable cutting forces were maintained up to 923 m/min, with temperatures exceeding 760 ℃ at speeds over 500 m/min and reaching 850 ℃ at 923 m/min. Microstructural analysis showed shear bands up to 20 µm deep under all conditions, and ultrafine ferrite and pearlite up to 5–8 µm deep at a speed of 923 m/min. Ferrite textures formed from the shear-deformed austenites were observed. Finite element analysis at 923 m/min revealed a severe cutting affected zone up to 10 µm deep, with temperatures, strains, and strain rates reaching 870 ℃, 5, and 200,000 /s, respectively, promoting a two-step phase transformation to form ultrafine grains under ultrahigh-speed and severe-shear conditions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Phase Transformations, Process Technology |