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Dynamic Constitutive Equations of Auto-Body Steel Sheets with the Variation of Temperature (I) - Dynamic Material Characteristics with the Variation of Temperature -

차체용 강판의 온도에 따른 동적 구성방정식에 관한 연구 (I) - 온도에 따른 동적 물성 특성 -

  • 이희종 (한국과학기술원 기계공학과) ;
  • 송정한 (한국과학기술원 기계공학과) ;
  • 박성호 (포스코 자동차강재연구센터) ;
  • 허훈 (한국과학기술원 기계공학과)
  • Published : 2007.02.01

Abstract

This paper is concerned with the thermo-mechanical behavior of steel sheet for an auto-body including temperature dependent strain rate sensitivity. In order to identify the temperature-dependent strain rate sensitivity of SPRC35R, SPRC45E and TRIP60, uniaxial tensile tests are performed with the variation of the strain rates from 0.001/sec to 200/sec and the variation of environmental temperatures from $-40^{\circ}C$ to $200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained from the static tensile test and that at the intermediate strain rate is obtained from the high speed tensile test. Experimental results show that the variation of the flow stress and fracture elongation becomes sensitive to the temperature as the strain rate increases. It is observed that the dynamic strain aging occurs with TRIP60 at the temperature above $150^{\circ}C$. Results also indicate that the flow stress and tincture elongation of SPRC35R are more dependent on the changes of strain rates and temperature than those of SPRC45E and TRIP60.

Keywords

Intermediate Strain Rate;Strain Rate Sensitivity;Temperature Sensitivity;Dynamic Strain Aging;Fracture Elongation

References

  1. Meyers, M. A., 1994, Dynamic Behavior of Materials, John Wiley & Sons, New York
  2. Campbell, J. D. and Ferguson, W. G.., 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
  3. Klepaczko, J. and Duffy, J., 1982, 'Strain Rate History Effects in Body-Centered-Cubic Metals,' ASTM STP765, pp.251-268
  4. Nemat-Nasser, S. and Guo, W. C., 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
  5. Nemat-Nasser, S. and Guo, W. C., 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
  6. ASM Handbook Committee, 1985, Metals Handbook 9th Ed. - Mechanical Testing, ASM. Metals Park, Ohio
  7. Lim, J. H., Kim, S. B., Kim, J. S., . Huh, H., Lim, J. D. and Park, S. H., 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
  8. Huh, H., Lim, J. H., Kim, S. B., Han , S. S. and Park, S. H., 2004, 'Formability of the Steel Sheet at the Intermediate Strain Rate,' Key Engineering Materials, Vols. 274-276, pp. 403-408 https://doi.org/10.4028/www.scientific.net/KEM.274-276.403
  9. Robinson, J. M. and Shaw, M. P., 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
  10. Huh, H., Lim, J. H., Song, J. H., Lee, K. S., Lee, Y. W and Han, S. S., 2003, 'Crashworthiness Assessment of Side Impact of an Auto-Body with 60 TRIP Steel for Side Member,' Int. J. Automotive Technology, Vol. 4, No.3, pp.149-156
  11. Zukas J. A., Nicholas, T., Swift, H. F., Greszczuk, L. B. and Curran, D. R., 1982, Impact Dynamics, John Wiley & Sons, New York
  12. Jones, N., 1989, Structural Impact, Cambridge University Press, Cambridge
  13. Liang, R. and Khan, A. S., 1999, 'A Critical Review of Experimental Results and Constitutive Models for BCC and FCC Metals over a Wide Range of Strain Rates and Temperatures,' Int. J. Plasticity, Vol. 15, pp. 963-980 https://doi.org/10.1016/S0749-6419(99)00021-2
  14. Lee, H. S. and Oh, Y. K., 2001, 'The Tensile Characteristics of Steel Sheets at Various Temperature Conditions,' Transactions of Materials Processing, Vol. 10, No. 2, pp. 101-110
  15. Hoge, K. G. and Mukherjee, A. K., 1977, 'Temperature and Strain Rate Dependence of the Flow Stress of Tantalum,' J. Mater Sci., Vol. 12, No. 8, pp. 1666-1672 https://doi.org/10.1007/BF00542818

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