Deformation Behavior and Evolution of Austenite Microstructure and Texture During Hot Compression of 5CrNiMoV Steel

Deformation behaviour of 5CrNiMoV steel was investigated at temperature 830–1230 °C and strain rate 0.001–10 s⁻¹. The flow curves were analyzed to illuminate the deformation characteristics. Comprehensive austenite microstructural investigation was carried out using optical microscope for deformed samples. It was found that discontinuous dynamic recrystallization mechanism played a leading part in the nucleation of dynamic recrystallization (DRX) nuclei and growth of DRX grains, and that the austenite grain size increased with deformation temperature, while a larger strain rate was conducive to grain refinement for the quickly generated strain storage-energy favorable for higher DRX nucleation rate. The parent austenite texture evolution and typical martensitic transformation texture for some deformed samples were characterized using electron backscattering diffraction technique and the software of the reconstruction of parent austenite. It was found that increasing temperature contributed to the increase of its maximum of random distribution (MRD) and the strength of rotated Cube texture component, which was probably for the behavior DRX and growth of DRX grains during the hot deformation. The rotated Cube was weakened with the strain rate rising, while the main texture component did not change significantly, which was due to the increase in number of active slip systems and grain fragmentation. Besides, the martensitic transformation texture was related to the parent texture for the variant selection.