DOI QR코드

DOI QR Code

Low-Cycle Fatigue in Quenched Boron Steel Sheet Due to Hot Stamping

열간 성형된 보론강판의 저주기 피로 특성

  • Received : 2010.05.26
  • Accepted : 2010.07.08
  • Published : 2010.10.01

Abstract

Boron steel sheet is suitable for fabricating automobile parts because it is very strong and has low weight. Recently, many car makers are investigating the feasibility of fabricating the chassis part of automobiles using boron steel. In order to use boron steel sheets to fabricate the chassis part of automobiles, much better material property of low cycle fatigue life as well as high formability during hot stamping is required. Therefore, the low-cycle fatigue life of hot-stamped quenched boron steel was investigated in this study. The fatigue life observed at low strain amplitude was longer than that of an as-received boron steel sheet. However, the fatigue life reduced at high strain amplitude because of the low ductility and low fracture toughness of martensite, which was produced as a result of hot stamping.

열간성형된 보론강판은 고강도특성이 필요한 자동차 부품에 널리 적용되고 있으며, 최근에는 샤시 부품에도 점차로 적용되고 있다. 샤시 부품으로 적용되기 위해서 고강도 특성뿐만 아니라 내피로특성이 동시에 요구되고 있어, 본 연구에서 열간성형된 보론강판의 저주기 피로특성을 연구하였다. 저주기 피로시험결과, 총변형률 진폭이 낮은 영역에서는 열간성형된 보론강의 피로수명이 현저히 높았지만, 높은 총변형률 진폭에서는 열간성형된 보론강의 마르텐사이트 조직특성인 낮은 연성과 파괴인성으로 인해서 보론강 원소재의 피로수명이 더 높음을 확인할 수 있었다.

Keywords

References

  1. Chae, M. S., Lee, G. D., Suh, Y. S., Lee, K. H. and Kim, Y. S., 2008, “Mechanical and Forming Characteristics of High-Strength Boron-Alloyed Steel with Hot Forming,” Trans. Mater. Process., Vol. 18. No. 3, pp. 236-244. https://doi.org/10.5228/KSPP.2009.18.3.236
  2. Bannantine, J. A., Comer, J. J. and Handrock, J. L., Fundamentals of Metal Fatigue Analysis, pp. 1-30.
  3. Sherman, A. M. and Davies, R. G., 1981, "The Effect of Martensite Content on the Fatigue of a Dual Phase Steel," Int. J. Fatigue, January, pp. 36-40.
  4. Chakraborti, P. C. and Mitra, M. K., 2005, “Room Temperature Low Cycle Fatigue Behaviour of Two High Strength Lamellar Duplex Ferrite Martensite (DFM) Steels,” Int. J. Fatigue, Vol.27, pp. 511-518. https://doi.org/10.1016/j.ijfatigue.2004.09.003
  5. Fournell, R.A., Grey, E.A. and Fine, M.E., 1976, “Fatigue Behaviour of a Precipitation Hardening Ni-Al-Cu Medium Carbon Steel,” Metall Trans A, Vol. I, No. 7, pp. 669-682.
  6. Thielen, P.N., Fine, M.E. and Fournelle, R.A., 1976, “Cyclic Stress Strain Relations and Strain Controlled Fatigue of 4140 Steel,” Acta Metall, Vol. 24, pp. 1-10. https://doi.org/10.1016/0001-6160(76)90140-1
  7. Klesnil, M. and Lukas, P., 1967, “Fatigue Softening and Hardening of Annealed Low Carbon Steel,” J Iron Steel Inst, pp. 746-749.
  8. Sarma, S., Padmanabhan, V. and Low, K.A., 1997, “Cycle Fatigue Behaviour of a Medium Carbon Microalloyed Steel,” Int J Fatigue, Vol.19, No. 2, pp. 135-140. https://doi.org/10.1016/S0142-1123(96)00060-6
  9. Mediratta, S.R., Ramaswami, V., Singh, V. and Rama Rao, P., 1990, “Low Cycle Fatigue of Dual Phase Steels Produced by Different Cooling Rates and a Ferrite-Pearlite Steel,” Scripta Metall, Vol. 24, pp. 793-797. https://doi.org/10.1016/0956-716X(90)90244-B
  10. Sankaran, S., Subramanya Sarma, V. and Padmanabhan, K.A., 2003, “Low Cycle Fatigue Behavior of a Multiphase Microalloyed Medium Carbon Steel,” Materials Science and Engineering A 345, pp. 328-335. https://doi.org/10.1016/S0921-5093(02)00511-7

Cited by

  1. A Study on the Relationship between Tensile and Low Cycle Fatigue Properties of High Strength Material vol.23, pp.2, 2014, https://doi.org/10.5228/KSTP.2014.23.2.110
  2. Study on Fatigue Characteristic of Suspension Part Using Hot Forming vol.37, pp.3, 2013, https://doi.org/10.3795/KSME-A.2013.37.3.339