Study on the Bauschinger effect with increasing of tensile strength in dual phase steel sheets

The purpose of this study is to investigate the deformation property, under a high strain rate, of high strength steel sheets. The influence of strain rate on the Bauschinger effect is clarified, and the relation between the mechanical property and this influence is formulized. In this study, three kinds (590MPa, 780MPa, 980MPa) of high strength steel sheets of the Dual Phase type were applied. Both the rolling direction and the transverse direction specimens are created, and the compressive-tensile tests are conducted on three conditions of strain rate 7.0x10(-3), 10 and 100/s. As a result, it is shown clearly in Dual Phase steels that the dependence of strain rate on the Bauschinger effect exists. In addition, with the transformation of material into high strength, it is demonstrated that consideration of the influence of the Bauschinger effect becomes increasingly important; however, the need for consideration of the dependence of the strain rate and the influence of strength anisotropy on the Bausehinger effect decrease for a material model in a numerical simulation.