Dynamic Recrystallization Behavior of Medium Carbon Cr-Ni-Mo-Nb Steel during Hot Deformation

Hot compression deformation behaviors of medium carbon Cr-Ni-MO-Nb steel were investigated at deformation temperatures ranging from 1 223 to 1 423 K and strain rates of 0. 1. 1 and 5 s(-1). Dynamic recovery (DRV) and dynamic recrystallization (DRX) were observed during the hot compression deformation. For all of the samples, DRX occurred at deformation temperatures above 1 323 K at different strain rates, while below 1 223 K, no DRX was observed. The activation energy of the tested steel was determined as 386. 06 kJ/mol. The ratio of critical stress to peak Stress and the ratio of critical strain to peak strain were 0. 835 and 0. 37, respectively. Kinetic equations interpreting the DRX behavior of the tested steel were proposed, and the corresponding parameters including the volume fraction and the average grain size were determined. Moreover, the microstructures induced under different deformation conditions were analyzed.