Effects of Strain-rate and Heat Generation at the Deformed Portion on Material Properties of High Strength TRIP Steel Sheet

Abstract

TRIP (Transformation-Induced Plasticity) steels has excellent combination of strength and ductility due to the higher strain hardening properties. There are many fundamental and scientific researches on the deformation behavior and ductility of TRIP steels. As a practical performance of automotive parts， it is necessary to understand effect of strain-rate on the deformation behavior in order to improve the crashworthiness of body structure by using the high strength steels. In high strain-rate deformation， the temperature at the deformed potion could be increased by plastic working. So it is important to investigate effects of both strain-rate and temperature on material properties in deformation on the TRIP steels. In this study， strain-rate sensitivity of 1180MPa TRIP is investigated focusing on the temperature effect in high strain-rate. As the results， the interaction of strain-rate and temperature effects shows the important role for the high-speed deformation for the TRIP steels.