About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Forming and Joining of Advanced Sheet Metal Materials
|
| Presentation Title |
Hole Expansion Ratio of Ferritic 1 GPa Low Carbon Low Alloyed Steel |
| Author(s) |
Antti Kaijalainen |
| On-Site Speaker (Planned) |
Antti Kaijalainen |
| Abstract Scope |
The stretch flangeability of ferritic steel grade with tensile strength ≥1 GPa in hole expansion tests can be significantly improved by using the wire electrical discharge machining (W-EDM) process for hole-making instead of conventional punching tools. This improvement is attributed to the notably enhanced cut edge quality of the machined holes. In this study, the average hole expansion ratio (HER) of a novel 0.1C-0.3V-0.25Mo-0.08Ti-0.08Nb steel increased from 24% to 91% when W-EDM was used in hole preparation. A comparison between the fractured surfaces of punched and W-EDM-machined holes after HER testing revealed different failure mechanisms in the steel sheet. At the onset of cracking, fractures in the W-EDM specimens exhibited ductile behavior, whereas quasi-cleavage fracture was observed in the punched specimens. Based on metallographic investigations, it was concluded that eliminating microstructural constituent variations improved the stretch flangeability of the Ti-Mo-V-Nb steel in both hole-making processes. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Shaping and Forming, Characterization |