Analysis of bending deformation in ferrite-martensite dual-phase steel sheets by using nanoindentation technique(T007_1)

摘要

Dual-phase steel sheets with high strength have been applied for reinforcing parts of automotive body. The steel sheets have excellent ductility due to containing a matrix of ductile ferrite plus a proportion of hard martensite. However, although bending is one of the most widely used processes in press forming, the steel sheets do not have enough bendability. Therefore, the improvement of bendability has been required. The effect of microstructures on bendability was investigated in high strength steel sheets. Bendability is related to a difference in hardness between ferrite and martensite 1).