Bending deformation behaviour of TRIP steel at several deflection rates

Abstract

Transformation induced plasticity (TRIP) steels manifest a high ductility and a high impact energy absorption characteristic because of strain induced martensitic transformation. Recently, some shock absorption members are being used for the automobile industry. In general, its dominant mechanism is bending deformation. If it is possible to apply TRIP steels to the shock absorption members, those members might possess much higher performance capability. The energy absorption characteristic and deformation behaviour of TRIP steels under bending deformation should be clarified. The purpose of the present study is to clarify rate sensitivity and deformation behaviour of TRIP steels subjected to bending moment. To achieve this aim, first, a prototype of an impact three‐point bending test apparatus based on the split Hopkinson pressure bar technique is established. The rate sensitivity of TRIP steels are investigated at various deflection rates using the established apparatus and a conventional material testing machine.

Keywords:

• TRIP steel
• Impact three‐point bending
• Split Hopkinson pressure bar
• Rate sensitivity
• Finite element method

The authors gratefully acknowledge the financial supports from the Amada Foundation for Metal Work Technology and the Japan Science and Technology Agency.