Abstract
Dual phase steels are characterized by a microstructure consisting of ferrite, martensite, retained austenite, and/or lower bainite. This microstructure can be altered by tempering with accompanying changes in mechanical properties. This paper examines such changes produced in a vanadium bearing dual phase steel upon tempering below 500 °C. The steel mechanical properties were minimally affected on tempering below 200 °C; however, a simultaneous reduction in uniform elongation and tensile strength occurred upon tempering above 400 °C. The large amount of retained austenite (≅10 vol pct) observed in the as-received steel was found to be essentially stable to tempering below 300 °C. On tempering above 400 °C, most of the retained austenite decomposed to either upper bainite (at 400 °C) or a mixture of upper bainite and ferrite-carbide aggregate formed by an interphase precipitation mechanism (at 500 °C). In addition, tempering at 400 °C led to fine precipitation in the retained ferrite. The observed mechanical properties were correlated with these microstructural changes. It was concluded that the observed decrease in uniform elongation upon tempering above 400 °C is primarily the consequence of the decomposition of retained austenite and the resulting loss of transformation induced plasticity (TRIP) as a contributing mechanism to the strain hardening of the steel.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
M.S. Rashid:SAE Trans., 1976, vol. 85, sec. 2, p.938.
M. S. Rashid:SAE Trans., 1977, vol. 86, sec. 2, p. 935.
B.V. N. Rao and A. K. Sachdev: General Motors Research Laboratories, Warren, MI 48090, Research Publication, GMR-3564, February 1981.
S. Hayami and F. Furukawa:Proc. Microalloying '75, Union Carbide, New York, NY, 1975, p. 311.
J. H. Bucher and E. G. Hamburg:SAE Trans., 1977, vol. 86, sec. 1, p. 730.
A. P. Coldren and G. Tither:J. Metals, 1978, vol. 30 (4), p. 6.
J. M. Righbee and P. J. VanderAhrend, “Formable HSLA and Dual Phase Steels,” Conference Proceedings, TMS-AIME, Warrendale, PA, AT. Davenport, ed., 1977.
S. Jin and D. Huang:Metall. Trans. A, 1976, vol. 7A, p. 745.
R. M. Horn and R. O. Ritchie:Metall. Trans. A, 1978, vol. 9A, p. 1039.
B.V. N. Rao and G. Thomas:Metall. Trans. A, 1980, vol. 11A, p. 441.
C.R. Simcoe:Trans. TMS-AIME, 1966, vol. 236, p. 1387.
G. R. Speich and W. C. Leslie:Metall. Trans., 1972, vol. 3, p. 1043.
B.V. N. Rao and M.S. Rashid: General Motors Research Laboratories, Warren, MI 48090, Research Publication, GMR-3565, February 1981.
P. Ostrom, B. Lonnberg, and I. Lindgren:Metals Technology, 1981, vol. 8, p. 81.
Author information
Authors and Affiliations
Additional information
B. V. N. RAO, formerly Senior Research Engineer, Analytical Chemistry Department, General Motors Research Laboratories
Rights and permissions
About this article
Cite this article
Rashid, M.S., Rao, B.V.N. Tempering characteristics of a vanadium containing dual phase steel. Metall Trans A 13, 1679–1686 (1982). https://doi.org/10.1007/BF02647823
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02647823