Characterization of a dual phase steel using tensile and free bending tests

Abstract

Accurate material characterization is needed for good simulation and process design and to achieve high quality standards in the automobile industry. Previous studies have shown that the material behaviour near the yield point is strongly affected by residual stress and recent investigations have revealed that tensile test data does not reflect well the effect of residual stresses. A test procedure promising a higher sensitivity to residual stress is the free bending test. In this work the difference between material data generated using the tensile test is compared with that obtained from a pure bending for a cold rolled Dual Phase high strength steel. Tensile tests and bending tests were performed on specimens oriented in the rolling, diagonal and transverse directions and material anisotropy and hardening studied. The results show that there are significant differences in material hardening and anisotropy between the material data generated by the tensile test and that obtained using the bending testing.