Hot Deformation Behavior and Thermal Processing Map of a High-Chromium Bearing Roller Steel

The thermal deformation mechanical behavior and recrystallization law of a high-chromium bearing roller steel were studied in a hot compression test in which the strain rates were 0.01-10 s-1 and the deformation temperatures were 950-1 200 ℃, using Gleeble-3500 thermal/power simulation test machine. The thermal processing map was drawn based on dynamic materials model. The results show that the thermal deformation equation could be described as =1.0×1018[sinh(0.008 3σ)]5.78exp[-481 363/(RT)], and the thermal deformation activation energy was 481.363 kJ·mol-1. The best deformation conditions of combination of temperature and stain rate were 1 045-1 170 ℃, 0.01-0.3 s-1 and 1 165-1 200 ℃, 1-10 s-1. The deformation mechanism was dynamic recrystallization, and the energy dissipation rate was more than 29%.