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A novel rolling technique, i.e., skew rolling, was applied to a non-oriented electrical steel containing 0.9 wt% Si, aiming at altering the texture of the final sheets that usually contain the magnetically unfavorable <111>//ND fiber after conventional rolling and annealing. The texture after skew cold rolling was compared to those obtained from conventional rolling and cross rolling and significantly different textures were observed. The cold-rolled steel sheets were then annealed and the texture evolution was investigated using a quasi in situ electron backscatter diffraction technique, i.e., tracking the microtexture of the same area at various holding times at the same temperature. The development of the recrystallization microstructure and microtexture (nucleation and grain growth) was characterized and the effect of skew rolling on the final texture was studied. The mechanisms governing the formation of the final recrystallization texture, e.g., preferential nucleation and selective growth, were elucidated. [ABSTRACT FROM AUTHOR]

The evolution of texture and microstructure during the annealing of a 0.88 wt% Si steel cold deformed by skew rolling was investigated using a quasi-in-situ electron backscatter diffraction (EBSD) technique. After skew rolling, a strong {001}〈130〉 texture and a typical γ-fiber texture (〈111〉//ND) develop. Upon annealing, the {001}〈130〉 grains gradually disappear and a strong {113}〈uvw〉 texture forms. Analysis of the misorientations between the deformed {001}〈130〉 grains and their neighboring recrystallized grains shows that the preferred growth of the {113}〈uvw〉 grains might be due to the high grain boundary mobility of these grains with respect to the deformed matrix. [ABSTRACT FROM AUTHOR]

Improving the magnetic properties of non-oriented electrical steel (NOES) through the optimization of crystallographic texture has been an on-going research activity for decades. However, using traditional rolling and annealing procedures, the obtained final textures were usually very similar, i.e., exhibiting the {111} (γ) and <110> (α) fibres, which were not the desired {001} texture (θ-fibre) for optimal magnetic quality. In the current work, a 1.8 wt% Si NOES was processed using a new sheet metal deformation method, i.e., repetitive bending under tension (R-BUT), also known as continuous bending under tension (C-BUT), to modify the texture of the electrical steel. The hot-rolled and annealed NOES plates were repeatedly bent and unbent when they were pulled under tension. The deformed plates were then heat treated at different temperatures for various times. Neutron diffraction and electron backscatter diffraction (EBSD) characterisation of the macro- and micro-textures proved that the R-BUT process significantly reduced the undesired {111} texture while promoting the {001} texture. The cube texture, which rarely formed after conventional rolling and annealing, was also seen in the R-BUT samples after annealing. It was shown that, the shear plastic deformation (induced by R-BUT) played a significant role in promoting the desired textures. In addition, the results indicated that the NOES processed by R-BUT could be deformed beyond its common formability limit, which may provide a method to address the poor workability challenge of high silicon electrical steels. [ABSTRACT FROM AUTHOR]