Quasi-in-situ observation: study on the evolution of the brass-texture in oriented silicon steel during the process of normalizing annealing

The presence of the brass texture ({110}<112>) impairs the magnetic properties of oriented silicon steel. However, the mechanism governing the evolution of this texture during normalizing annealing remains unresolved. In this study, the nucleation and growth behavior of the brass texture were systematically investigated during the normalizing process. Further, the microstructure of hot-rolling sheets during the normalizing process was characterized by quasi-in-situ electron backscatter diffraction and an independently developed image registration technique. During the initial stage of growth of brass-oriented grains, small-sized grains are more dependent on Coincidence Site Lattice (CSL) grain boundaries, the low interfacial energy of the Σ7 and Σ9 enables the grains to grow rapidly at the grain boundary. brass orientation grains offer an advantage over Copper and Goss orientation grains in competitive growth. With the exception of the brass orientation grains that nucleate and grow within the center layer, all other brass orientation grains exhibit oriented growth. Although deformation energy storage and initial grain size exhibit relatively minor effects, the growth of quasi-brass orientation grains is highly sensitive to environmental conditions. Directly growing brass orientation grains located at the same spatial position offer a slight advantage over grains formed by nucleation and growth steps. The growth status of directly growing brass orientation grains at different spatial locations shows that Σ9 contributes more than Σ7. The growth behavior of nucleated and growing grains at different spatial locations shows that the CSL relationship dominates the contribution to grain growth, while the contribution of interfacial energy is relatively weak.