Effect of the Continuous Annealing Process on Microstructure and Mechanical Properties of DP590 Steel

Abstract

The microstructure and mechanical properties of the continuous annealing DP590 steel produced by a cold rolled plant were studied by utilizing a Gleeble thermal simulator tested machine. The results show that, increasing annealing temperature can not effectively improve the martensite content in the steel and annealing temperature be set at 780 °C and 800 °C is rational. Martensite decomposition at high overaging temperature will decrease tensile strength of the samples. As the overaging temperature sets at 250 °C ~ 300 °C, the samples could achieve tensile strength more than 600 MPa, which meet the requirements of DP590.