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A Study on the Strain-Rate Sensitivity According to the Temperature for Steel Sheets of an Auto-Body

차체용 강판의 온도에 따른 변형률속도 민감도 연구

  • 이희종 (한국과학기술원 기계공학과) ;
  • 송정한 (한국과학기술원 기계공학과) ;
  • 조상순 (한국과학기술원 기계공학과) ;
  • 박성호 (POSCO 기술연구소) ;
  • 허훈 (한국과학기술원 기계공학과)
  • Published : 2006.03.01

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 $-40^{\circ}C\;to\;200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and at 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 of strain-rate and temperature than those of SPRC45E.

References

  1. J. D. Campbell, W. G. Ferguson, 1970, Temperature and Strain Rate Dependence of The Shear Strength of Mild Steel, Phil. Mag. Vol. 21, No. 169, pp. 63-82 https://doi.org/10.1080/14786437008238397
  2. J. Klepaczko, J. Duffy, 1982, Strain Rate History Effects in Body-Centered- Cubic Metals, ASTM STP765, pp. 251-268
  3. S. Nemat-Nasser, W. C. Guo, 2001, Thermo mechanical Response of AL-6XN Stainless Steel over a Wide Range of Strain Rates and Temperatures, J. Mech. Phys. Solids, Vol. 35, pp. 1823-1846
  4. S. Nemat-Nasser, W. C. Guo, 2003, Thermo mechanical Response of DH-36 Structural Steel over a Wide Range of Strain Rates and Temperatures, Mech. Mater., Vol. 35, pp. 1023-1047 https://doi.org/10.1016/S0167-6636(02)00323-X
  5. J. H. Lim, S. B. Kim, J. S. Kim, H. Huh, J. D. Lim, S. H. Park, 2005, High Speed Tensile Test of Steel Sheets for an Auto-body at the Intermediate Strain Rate. Transaction of KSAE, Vol. 13, No. 2, pp. 127-134
  6. 임지호, 허 훈, 권순용, 윤치상, 박성호, 2004, 중변형률속도에서의 차체용 강판의 동적 인장실험, 대한기계학회 춘계학술대회, pp. 1669-1974
  7. K. Mahadevan, R. McCoy, B. Schell, J. Fekete, 1998, Strain-Rate Characterization of Automotive Steel and the Effect of Strain-Rate in Component Crash Analysis, SAE 982392
  8. J. M. Robinson, M. P. Shaw, 1994, Microstructural and Mechanical Influences on Dynamic Strain Aging Phenomena, Int. Mater. Rev., Vol. 39, pp. 113-122 https://doi.org/10.1179/imr.1994.39.3.113
  9. H. Huh, J. H. Lim, S. B. Kim, S. S. Han, S. H. Park, 2004, Formability of the Steel Sheet at the Intermediate Strain Rate, Key Engineering Materials, Vols. 274-276, pp. 403-408
  10. 이항수, 오영근, 2001, 박강판의 온도변화에 따른 인장특성, 한국소성가공학회지, 제 10 권, 제 2 호, pp. 101-110