Texture-Type Analysis of Fe2O3 and Fe3O4 Oxide Layers on the Surface of High-Strength Steel

The grain boundary characteristics of oxide scales affect the surface quality and fracture behavior of steel plates during hot rolling. In the present work, the electron backscatter diffraction technique was used to investigate the texture evolution behavior of magnetite (Fe3O4) and hematite (Fe2O3) in the deformed oxide layer of high-strength steel. The results show that Fe3O4 formed a γ texture parallel to the oxide growth direction, whereas Fe2O3 formed a component with {0001}<10 ({overline{ ext{1}}}) 0> texture. High thickness reduction rates of > 27% reduced the wedge of Fe2O3 into Fe3O4 grains through cracks and hindered the formation of internal cracks. In comparison with Fe3O4 and Σ3a, when Σ13b and Σ19b grain boundaries existed in Fe2O3, the scale was more likely to crack. Therefore, appropriate grain boundary engineering methods must be used to improve the required grain boundary type and suppress crack propagation. Finally, avoiding the growth of Fe2O3 along the <111> grain direction of Fe3O4 grains at an angle of 55° can greatly reduce the disturbance from Fe2O3 during hot rolling.