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A 0.23 mm thick grain-oriented silicon steel sheet was successfully produced based on strip casting and two-stage cold rolling route. The evolutions of microstructure and texture along the complete processing route were briefly investigated. It was shown that the as-cast strip was composed of coarse ferrite grains and martensite, and the texture was mainly characterized by strong {001} $\langle 0vw\rangle $ texture. Goss texture was absent in the hot-rolled strip, which was distinct from the well accepted results that Goss texture had its origin during hot rolling. After the cycle of the first-stage cold rolling, an intermediate annealing, the second-stage cold rolling, and a primary annealing, the strip exhibited a fully recrystallized microstructure with a weak \alpha $ -fiber texture and a relatively strong \gamma $ -fiber texture. Goss texture was not observed through the thickness of the primary annealed strip. This was significantly different from the previous results that Goss texture was the most populous component in the primary recrystallization texture of two-stage route in conventional process. After secondary recrystalization annealing, the magnetic induction of the sheet was as high as 1.84 T. [ABSTRACT FROM AUTHOR]

• Low-finishing-temperature hot rolling and batch annealing result in large grains. • Prior large grains lead to desirable recrystallization microstructure and texture. • A potential processing method to improve magnetic properties is proposed. The grain size prior to cold rolling plays an important role in the microstructural, textural evolution and magnetic properties of non-oriented silicon steel sheets. In this work, we proposed a new way to obtain large grain size before cold rolling and applied it to a 1.0 wt% Si-0.2 wt% Al non-oriented silicon steel, i.e., appropriate low-finishing-temperature hot rolling combined with batch annealing. The grain growth process during batch annealing was investigated using a quasi in-situ electron backscattered diffraction (EBSD) technique. It was demonstrated that significant grain growth took place through a strain-induced boundary migration mechanism. Then a large number of in-grain shear bands were formed in the cold rolled microstructure and could provide nucleation sites for Goss ({1 1 0} 〈0 0 1〉) and λ-fiber (〈0 0 1〉//ND) recrystallized grains, thus resulting in a coarse-grained and homogeneous recrystallization microstructure with weakened γ-fiber (〈1 1 1〉//ND) texture, strengthened Goss and λ-fiber texture. Consequently, superior magnetic properties (B 50 = 1.763 T, P 1.5/50 = 4.30 W/kg) were obtained. For comparison, the conventional processing route without batch annealing was also investigated. A small-grained and inhomogeneous recrystallization microstructure with pronounced γ-fiber texture was produced in the finally annealed sheet, which could significantly deteriorate both the magnetic induction and iron loss. This work provided a new way to enlarge the grains in hot rolled sheets by low temperature batch annealing instead of the conventional high temperature normalization. Thus a new processing route to fabricate low silicon non-oriented electrical steels with high permeability and low iron loss was established. [ABSTRACT FROM AUTHOR]

• Ultra-thin sheets were produced based on primary recrystallization. • Dependence of texture evolution on initial Goss orientation was clarified. • Different cold rolled and recrystallization textures evolved in Hi-B and CGO. • Mechanism of recrystallization of typical texture was investigated. • Relationships of iron loss upon grain size, texture and thickness were clarified. Based on cold rolling and primary recrystallization method, 0.05–0.15 mm-thick ultra-thin grain-oriented silicon steel sheets were successfully produced by utilizing the high induction (Hi-B) and common grain-oriented (CGO) silicon steels as raw materials, respectively. Thus, the effects of sharpness of initial Goss texture on the evolutions of microstructure, texture and magnetic property were investigated in detail. For Hi-B steel, 'smooth' microstructures were formed in the cold-rolled sheets, and the textures evolved along the following path: exact {1 1 0}〈0 0 1〉 → {2 3 0}〈0 0 1〉 → {1 1 1}〈1 1 2〉. By contrast, significant deformation bands or shear bands were observed in the CGO steel, and the textures developed along the following path: deviated {1 1 0}〈0 0 1〉 → {2 1 0}〈0 0 1〉 → {1 1 1}〈1 1 2〉. After annealing, inhomogeneous microstructures containing some clusters with large grains (∼2–4 mm) and fine equiaxed grains appeared in the Hi-B steel and the associated texture evolution with increasing cold rolling reduction followed the path: {1 1 0}〈0 0 1〉 → {2 3 0}〈0 0 1〉 → {2 1 0}〈0 0 1〉. Unlike the Hi-B steel, relatively fine and uniform equiaxed recrystallization grains were produced in the final CGO steel, and the texture evolved along the route: {2 1 0}〈0 0 1〉 → {6 1 0}〈0 0 1〉. Consequently, further research focusing on the recrystallization mechanism was studied. The results showed that {1 1 0}〈0 0 1〉 and {2 1 0}〈0 0 1〉 developed into the predominated components due to oriented growth and oriented nucleation respectively in the 0.05 mm-thick Hi-B sheet, while {1 0 0}〈0 0 1〉 became the main texture with the aid of oriented nucleation advantage in the CGO sheet. In addition, more attention was paid on the magnetic properties of the ultra-thin sheets, and the results showed that heavy cold rolling reduction as well as low annealing temperature contributed to better magnetic induction. Furthermore, the separated iron loss components were obtained to clarify the relationships between the iron loss and grain size, texture and thickness. [ABSTRACT FROM AUTHOR]

• Effect of two-stage cold rolling route on microstructure and texture was studied. • Low-reduction cold rolling and intermediate annealing resulted in coarse grains. • γ-Fiber was weakened while λ-fiber and Goss texture were enhanced in final sheet. • Increasing grain size prior to cold rolling led to improved magnetic properties. The 0.5 mm-thick Fe-0.9 wt%Si-0.3 wt%Al non-oriented electrical steel sheets were successfully produced with one-stage and two-stage cold rolling methods. The comparative investigations were conducted on the relationships between the processing routes, microstructures, textures and magnetic properties. This study mainly focused on how to increase the grain sizes prior to cold rolling and its influences on subsequent microstructure and texture evolution. The results showed that the fine microstructure prior to final cold rolling led to the pronounced γ-fiber texture, fine recrystallized grains and deteriorated magnetic properties after final annealing. Nevertheless, by introducing a low-reduction cold rolling and intermediate annealing, coarse grains could be generated prior to the final cold rolling. When the cold rolling reduction was 11%, a relatively homogeneous microstructure composed of fully coarse grains was produced. The increased grain sizes promoted the generation of dense shear bands during final cold rolling, which served as the nucleation sites for λ-grains and Goss grains. This resulted in the improved magnetic properties due to the weakened γ-fiber texture, strengthened λ-fiber texture and Goss texture and increased grain sizes in the final annealed sheets. This work provided a new way to improve the magnetic properties of non-oriented electrical steels by controlling the grain sizes prior to final cold rolling. [ABSTRACT FROM AUTHOR]