차체용 강판의 온도에 따른 변형률속도 민감도 연구

Abstract

This paper is concerned with the thermo-mechanical behavior including temperature dependent strain-rate sensitivity of steel sheet for an auto-body. In order to identify the temperature dependent strain-rate sensitivity of SPRC35R and SPRC45E, uniaxial tension tests are performed with the variation of the strain-rates from 0.001/sec to 200/sec at environmental temperatures varied from -40℃ to 200℃. the thermo-mechanical response at the quasi-static state is obtained with the static tensile test and the intermediate strain-rate is from the high speed tensile test. Experimental results show that the strain-rate sensitivity increases at low temperature. It represents that as the strain-rate increases, the variation of flow stress becomes sensitive on the temperature. The results indicate that the Flow stress of SPRC35R is more dependent on the changes og strain-rate and temperature than those of SPRC45E.