- SPRC440 강판재의 미세조직 구성이 동적 인장 특성에 미치는 영향
- ㆍ 저자명
- 이성희,임영목,이정환,김인배,김양도,Lee. S.H.,Rhyim. Y.M.,Lee. J.H.,Kim. I.B.,Kim. Y.D.
- ㆍ 간행물명
- 소성가공
- ㆍ 권/호정보
- 2011년|20권 4호|pp.309-315 (7 pages)
- ㆍ 발행정보
- 한국소성가공학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
The behavior of metallic materials at high strain rates shows different characteristics from those in quasi-static deformation. Therefore, the strain rate should be considered when simulating crash events. The objective of this paper is to evaluate the dynamic tensile characteristics of SPRC440 as a function of the volume fraction of phases. As-received SPRC440 is composed of ferrite and pearlite phases. However, ferrite and martensite phases were observed after heat treatment at $730^{circ}C$ and $780^{circ}C$ for 5 minutes, as expected by calculations based on the curves from dilatometry tests. High cross-head speed tensile tests were performed to acquire strain-stress curves at various strain rates ranging from 0.001 to $300;s^{-1}$, which are typical in real vehicle crashes. It was observed that the flow stress increases with the strain rate and this trend was more pronounced in the as-received specimens consisting of ferrite and pearlite phases. It is speculated that the dislocation density in each phase has an influence on the strain rate sensitivity.