Contact Pressure Dependent Frictional Characteristics of Hot-Dip Galvanized High Strength Steel Sheet and its Effect on Springback Behavior

Abstract:

The application of high strength steel sheet on stamping part extends the range of contact pressure than that of mild steel’s and makes the effect of contact pressure on frictional characteristics of steel sheet a regardable fact. The friction test with hot-dip galvanized high strength steel sheet was conducted under various contact pressures, to investigate the influence of contact pressure on frictional behavior of steel sheet. According to the test result, the contact pressure effect on friction is considerable. The friction between tool and work-piece influences the stress distribution during stamping process. To investigate the influence of frictional behavior on stress distribution at stamped part, the U-draw bending under constant blank holding force with different blank size were conducted and it was verified by finite element analysis with and without considering contact pressure effect on frictional behavior. As the result of study, the variation of frictional behavior depending on contact pressure results changes in the stress distribution of parts that has effects on tendency of springback for high strength steel sheet stamping.

• Periodical: Key Engineering Materials (Volumes 535-536)
• Pages: 250-253
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.535-536.250
• Online since: January 2013
• Authors: Soo Sik Han
• Keywords: Blanking Holder Pressure, Galvanized Steel, High Strength Steel (HSS), Oil Pocket, U-Draw Bending

References

[1] A. Azushima, M. Sakuramoto, Effects of Plastic Strain on Surface Roughness and Coefficient of Friction in Tension-bending Test, Annals of the CIRP 55 (2006) 1-4.

DOI: 10.1016/s0007-8506(07)60422-3

[2] W. T. Kim, D. H. Lee, M. S. Suh, Y. H. Moon, Analysis on parameters affecting the friction coefficient in drawbead forming of sheet metal, Transactions of Mat. Proc. 14 (2005) 668-674.

DOI: 10.5228/kspp.2005.14.8.668

[3] J. M. Lanzona, M. J. Cardew-Hall, P. D. Hodgson, Characterising frictional behaviour in sheet metal forming, J. Mat. Proc. Tech. 80–81 (1998) 251-256.

DOI: 10.1016/s0924-0136(98)00110-1

[4] S. S. Han, D. J. Kim, Contact Pressure Effect on Frictional Characteristics of Steel Sheet for Autobody, AIP Conf. Proc. for Numisheet2011 1383 (2011) 780-783.

DOI: 10.1063/1.3623685

[5] S. S. Han, K. C. Park, J. B. Nam, A study on shape fixability of press formed parts, Transactions of Mat. Proc. 8 (1999) 38-46.