Dual Phase Steel Characterization for Tube Bending and Hydroforming Applications

Abstract:

The behaviour of dual phase steel tubes at 600, 780, and 980 MPa strength grades undergoing rotary draw bending and pressure sequence hydroforming is examined. Bending was performed using three different bend ratios. Principal strains were measured at several locations on each tube. It was found that the level of strain experienced by the tubes was independent of steel grade. The outcome of the bending process was stochastic in nature; for a given steel grade and bend ratio, some tubes were successfully formed, while others experienced failure. The proportion of failed tubes was found to increase with higher strength steel grades and tighter bend ratios. Metallographic samples from the extrados of the bent tubes revealed that many of the same microstructural features affecting strength and elongation in uniaxial tensile testing, namely martensite banding and non-metallic inclusions, affected dual phase steel tubes undergoing rotary draw bending. Additionally, a nanoindentation technique was investigated to determine the potential for more detailed microstructural characterization.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 2066-2071
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.2066
• Online since: January 2012
• Authors: Chad Oliver, Randy J. Bowers, Daniel E. Green
• Keywords: Dual Phase Steel, Hydroforming, Martensite Banding, Nano Indentation

References

[1] G. Khodayari: SAE International Journal of Materials and Manufacturing Vol. 1 No. 1 (2009) pp.841-848.

[2] Y.J. Park, A.P. Coldren and J.W. Morrow in: Fundamentals of Dual Phase Steels by R.A. Kot and B.L. Bramfitt, TMS-AIME (1981) pp.485-497.

[3] J. Lis, A.K. Lis and C. Kolan: Journal of Materials Processing Technology Vol. 162-163 (2005) pp.350-354.

DOI: 10.1016/j.jmatprotec.2005.02.105

[4] Y. Tobiyama, K. Osawa and M. Hirata: Kawasaki Steel Giho Vol. 31 No. 3 (1999) pp.181-184.

[5] K.W. Andrews: Journal of the Iron and Steel Institute Vol. 203 (1965) pp.721-727.

[6] T. Irie, S. Satoh, K. Hashiguchi, I. Takahashi and O. Hashimoto: Transactions of the Iron and Steel Institute of Japan Vol. 21 (1981) p.793.

DOI: 10.2355/isijinternational1966.21.793

[7] G.R. Speich and R.L. Miller in: Structure and Properties of Dual-Phase Steels by R.A. Kot and J.W. Morris, TMS-AIME (1979) pp.145-182.

[8] I.A. El-Sesy and Z.M. El-Baradie: Materials Letters Vol. 57 (2002) pp.580-585.

[9] K.K. Chawla, P.R. Rios and J.R.C. Guimaraes: Journal of Materials Science Letters Vol. 2 No. 3 (1983) pp.94-98.

[10] A.F. Szewczyk and J. Gurland: Metallurgical and Materials Transactions A Vol. 13A No. 10 (1982) pp.1821-1826.