Hot deformation behaviors and microstructure characteristics of Cr-Mo-Ni-V steel with a banded structure

On a Gleeble-3800 thermal simulator, the hot deformation behavior of Cr-Mo-Ni-V steel was studied, with the designed deformation temperature varying from 900 to 1,200 degrees C and the strain rate in the range of 0.01-10 s-1. It was observed that as the strain rate was increased and the hot working temperature was reduced, the flow stress of the experimental steel increased. The study also evaluated the safe parameters for deformation of the Cr-Mo-Ni-V steel in the hot working process, based on the established processing maps. It was found that the deformation temperature window varying from 1,050 to 1,150 degrees C and the reasonable strain rate in the range of 0.01-1 s-1 are beneficial to the hot deformation of the steel. In this research, the effect of processing parameters of the hot working process on the microstructure evolution of the banded structure was also investigated. According to the research result, the banded structure in the steel remained visible under the conditions of a strain rate of 10 s-1 and the hot working temperature in the range of 900-1,200 degrees C. However, it should be noted that the banded structure in the steel then gradually disappeared when the hot working temperature was increased to 1,200 degrees C.