Effect of Dynamic Recrystallization on the Transformed Ferrite Microstructures in HSLA Steel

Abstract

The flow stress behavior of high-strength low-alloy (HSLA) steel at different true strains was studied using a hot compression test. The effect of dynamic recrystallization (DRX) on the transformed ferrite microstructures was investigated with electron backscatter diffraction (EBSD). The EBSD analysis indicated that the fraction of high-angle grain boundaries (HAGBs) and DRX increased with increasing true strain. The low-angle grain boundaries (LAGBs) were gradually transformed into HAGBs with increasing DRX degree. When the true strain was increased to 0.916, the fraction of HAGBs increased to 85% and the fraction of DRX increased to 80.3%. The relatively high fraction of HAGBs was related to the complete DRX. The dislocations and substructures in the tested steel at different true strains were characterized by transmission electron microscopy (TEM). TEM observation shows that the nucleation of the dynamically recrystallized grains occurred by the bulging of the original grain boundaries. The DRX nucleation mechanism of the HSLA steel is the strain-induced grain boundary migration mechanism.

Effects of Lubricating Conditions on Wear Performance of U77MnCrH Rail

“…It leads to the densest deformation microstructure. In addition, under the dry condition, in the surface deformation layer, the process of dynamic recovery and recrystallization is easier to occur due to the highest friction temperature and deformation stress [27][28][29]. Therefore, the hardness value under the dry condition is lowest on the top 50 µm deformation layer, while it is highest under the grease lubrication condition.…”