Complete Goss Secondary Recrystallization by Control of the Grain Size and Texture of Primary Recrystallization in Grain-Oriented Silicon Steel

Matrix microstructure and texture controlling is an important way to optimize Goss ({110}<001>) abnormal grain growth (AGG) in high magnetic induction grain-oriented silicon (Hi-B) steel during primary recrystallization. In the present work, a matrix with homogeneous grain size and favorable texture components was obtained through two-stage normalized annealing followed by primary recrystallization. Furthermore, secondary recrystallization was performed for sharp Goss orientation by slow heating and purified annealing. It was found that plenty of island grains, which occurred and disappeared gradually, accompanied the process of AGG. Through analyzing the evolution of microstructure and texture, we realized that the formation of island grains was related to the large-size grains in matrix, and the elimination of that was attributed to the special grain boundaries which satisfied both coincident site lattice (CSL) and high-energy (HE) models. It was essential to control grain size and favorable orientations in matrix comprehensively for the high-efficient abnormal growing of sharp Goss orientation, through which excellent magnetic properties could be obtained simultaneously.

Effect of Normalization Process on the Microstructure and Properties of Annealed Cold-Rolled Sheet of Oriented Silicon Steel

Research object of this article is a type of oriented silicon steel in 3.07% silicon content. By comparing samples under normalization and non-normalization respectively after primary recrystallizing annealing and secondary recrystallizing annealing, we have figured out how normalization influenced the recrystallizing behavior. The EBSD data of samples showed that normalization can half the grain size after primary recrystallizing, raise the percentage content of favored grain boundaries and high-angle grain boundaries, increase the content of Goss orientation grains by 5 times. And normalization coarsens the secondary recrystallizing grains, triples the magnetic induction and reduces the iron loss by half.