Effect of Zr on microstructure evolution of Ti-Mo composite microalloyed steel during rolling

In this paper, the effect of Zr addition on the microstructure evolution of Ti-Mo composite microalloyed steel during austenitizing and rolling was investigated. The rolling process was simulated by Gleeble3500, and the microstructure of the rolling process was characterized by optical microscope, scanning electron microscope, and transmission electron microscope observation. The results show that the addition of Zr significantly refines the original austenite grains, increases the recrystallization temperature of Ti-Mo steels, and promotes the dispersion of fine second phase during the coiling process. At the same coiling temperature, the addition of Zr resulted in an increase in the hardness of Ti-Mo steel. And under the condition of containing Zr, the optimal microstructure and highest strength are achieved with soaking at 1200 °C, final rolling at 850 °C, and coiling at 600 °C.