Analysis of flow stress and microstructure evolution of 9310 steel during the hot compression

Abstract

Due to the low-cost and high-strength of carburizing 9310 steel, it has become widely used in the manufacturing industry especially gears and shafts manufacturing. Hence, this paper investigates the hot deformation behavior and microstructure evolution of the 9310 steel under hot compression conditions. With the help of a combination of standard compression testing, optical microstructure and electron backscatter diffraction (EBSD) observation experiment, the dynamic recrystallization (DRX) and dynamic recovery (DRV) mechanisms of the 9310 steel under compressive stress were determined and the constitutive equation model was also identified. It was found that the peak stress level, steady flow stress, dislocation density and number of substructures of the alloy increases with the decreasing of deformation temperature and the increasing of strain rate. Conversely, the high angle grain boundary area becomes larger, the grain boundary forms a serrated shape and the DRX in the alloy occurs. This comprehensive characterization of stress and phase transformation could enable a precise control of the microstructures of 9310 steel, and hence its properties.

Keywords

• 9310 steel
• microstructure evolution
• flow stress
• hot compression
• dynamic recovery
• dynamic recrystallization