Austenite dynamic recrystallization of the microalloyed forging steels 38MnVS during forging process

According to the deformation characteristics of the microalloyed forging steels used in automobiles, the austenite dynamic recrystallization of microalloyed forging steels 38MnVS was investigated by thermal simulation test enginery Gleeble-3800 with the stain rate of 0.1-10 s-1 at 950-1150.The effects of the deformation temperature and rate on the austenite dynamic recrystallization were investigated. The austenite dynamic recrystallization's activation energy was calculated. A mathematical expression as variables of the critical strain ɛc, peak strain ɛp, steady strain ɛs and the austenite grain size were obtained, and an equation as a variable of the Zener-Hollomon parameter Z was established. The state chart of the dynamic recrystallization of the microalloyed forging steel 38MnVS was made according to the experimental data and the deformation parameters, and the product quality is improved by optimizing the forging processing.