Incremental Bending of Ultra-High-Strength Steels
| Periodical | Key Engineering Materials (Volume 473) |
|---|---|
| Main Theme | Sheet Metal 2011 |
| Edited by | J.R. Duflou, R. Clarke, M. Merklein, F. Micari, B. Shirvani and K. Kellens |
| Pages | 53-60 |
| DOI | 10.4028/www.scientific.net/KEM.473.53 |
| Citation | Antti Määttä et al., 2011, Key Engineering Materials, 473, 53 |
| Online since | March, 2011 |
| Authors | Antti Määttä, Kari Mäntyjärvi, Jussi A. Karjalainen |
| Keywords | Bending, Incremental Forming, Roll Forming, Sheet Metal, Ultra High-Strength Steel |
| Price | US$ 28,- |
Utilisation of ultra-high-strength steels (UHS) has increased, particularly in the automotive industry. By using these materials vehicle structures can be lightened. However, one of the problems of UHS is weak formability. Materials fracture easily with small bending radii and the minimum bending radii are rather large. In this study, the tested materials were complex phase (CP) bainitic-martensitic UHS steels (YS/TS 960/1000 and 1100/1250). The steels were incrementally bent with a press brake in the rolling direction and perpendicular to it, and the final bending angle was 90 degrees. The incremental bending angles were 150°, 130°, 110° and 90°. The punch was unloaded after every incremental bending step. The test materials were bent with different bending radii. The aim was to find the minimum bending radius which produces an acceptable bend. Every incremental bend was compared with a bending performed in the traditional manner. The aim of this study was to examine how well the results of incremental bending compare to roll forming. In addition, clarification studies of when the bend started to fracture were made. It is well known that steels are more efficiently bent by roll forming compared with traditional bending. The results presented in this study demonstrate that incremental bending does not produce better results than traditional bending. Nevertheless, it has been shown that the examined steels can be bent incrementally against manufacturer’s recommendations.
