Evaluation of the Heat Treatment Response of a Multiphase Hot-Rolled Steel Processed by Controlled Rolling and Accelerated Cooling

Abstract

The tensile properties of hot-rolled multiphase steel after heat treatment were analyzed on a laboratory scale. Subcritical treatments applied to the hot-rolled strip revealed an increase in the yield stress and elongation with increasing temperature. Normalizing of the strip at 920°C notably improved the ductile response, while both the yield stress and the anisotropy of every property evaluated at 0°, 45°, and 90° to the rolling direction in the rolling plane were significantly reduced.

Keywords:

• Annealing
• Bainite
• Controlled rolling and cooling
• Ductility
• Ferrite
• Heat treatment
• Hot rolling
• Light optical microscopy (LOM)
• Lüders strain
• Martensite
• Mechanical properties
• Multiphase steels
• Normalizing
• Retained austenite
• Structural steels
• Subcritical annealing
• Tempering
• Tension test
• Tensile strength
• Yield stress

ACKNOWLEDGMENTS

The authors are grateful to the International Office of the University of Oviedo for the granting of an exchange grant to support J. T. Panta, and to Dr. G. F. Vander Voort to carry the proofreading of the English version of the manuscript.