Measurement and Analysis of Time-Temperature-Transformation Curves of Boron Steel 22MnB5
Hot stamping of quenchable boron steels is a new and complex forming technology integrating metal hot forming and quenching process. In order to gain the Time – Temperature - Transformation (TTT) curves of 22MnB5, the phase-transformation temperatures of boron steel 22MnB5 are measured by DIL 805A/D quenching and deformation dilatometer. According to the expansion curves of phase-transformation at some constant temperatures, the start and finish temperatures of phase-transformation are calculated by using the expansion method and the tangential method. The types of metallographic phases after phase-transformation are judged by the optical microscope and micro hardness. The TTT curves of 22MnB5 are drawn in terms of the results of testing and calculating.
L. F. He et al., "Measurement and Analysis of Time-Temperature-Transformation Curves of Boron Steel 22MnB5", Applied Mechanics and Materials, Vols. 29-32, pp. 484-489, 2010