Effects of cold rolling routes on microstructure, texture evolution, and magnetic anisotropy of ultra-thin non-oriented electrical steel

Achieving excellent magnetic properties and controlled magnetic anisotropy remains highly challenging for ultra-thin non-oriented electrical steel. In this study, 0.10 mm-thick 3.3Si-0.7Al (wt.%) non-oriented electrical steel was fabricated using one-stage and two-stage cold rolling routings with normalization, and two-stage cold rolling routing without normalization, respectively. The microstructure, texture evolution and magnetic properties were investigated comparatively. In particular, correlation between recrystallization texture, grain size, and magnetic anisotropy was revealed in detail. The one-stage cold rolling route finally produced the strongest γ- (<111>//ND) and α*-fiber ({1 1 h}<1 2 1/h>) recrystallization textures, and the smallest average grain size. Thus the lowest nominal magnetic induction B 50 , the highest nominal iron losses P 10/400 and P 10/1000 , and the lowest anisotropy in both iron loss and magnetic induction were displayed. In contrast, the two-stage cold rolling route without normalization finally produced stronger η- (<100>//RD) but weaker γ-fiber recrystallization texture, and bigger average grain size, hence higher nominal B 50 and lower nominal P 10/400 and P 10/1000 were obtained. The anisotropy of texture factor and grain size was much higher, resulting in higher anisotropy in magnetic induction and iron loss. For the two-stage cold rolling route with normalization, the λ-fiber (<001>//ND) recrystallization texture was finally formed along with the strongest η- but the weakest γ-fiber texture, and the largest average grain size. As a result, the highest nominal B 50 , and the lowest nominal P 10/400 and P 10/1000 were acquired. However, the highest anisotropy of texture factor and grain size led to the highest anisotropy in magnetic induction and iron loss.