Evolution law of texture in grain-oriented electrical steel ultra-thin strips

Grain-oriented silicon steel ultra-thin strip shows broad application prospects in high-frequency power electronic devices due to its excellent magnetic properties. Its texture evolution directly affects the magnetic properties of the final product, and the annealing temperature is a key process parameter for controlling texture and magnetic performance. To investigate the texture evolution during the preparation of grain-oriented silicon steel ultra-thin strip and the influence of annealing temperature on microstructure, texture, and magnetic properties, a commercial substrate- glassless grain-oriented electrical steel sheet with thickness of 0.27 mm was used as raw material. An ultra-thin strip with thickness of 0.08 mm was prepared via single cold-rolling method. The specific process involved two-pass cold rolling, first pass reduction rate 63% and second pass 20%, followed by high-temperature annealing of the cold-rolled ultra-thin strip at different temperatures ranging from 800 to 940 ℃. The research primarily employed characterization techniques such as electron backscatter diffraction（EBSD） micro-texture analysis and X-ray diffraction （XRD） to systematically analyze the evolution of microstructure and texture during the cold rolling and annealing processes of the grain-oriented silicon steel ultra-thin strip. Experimental results indicate that the initial sample is dominated by Goss texture. After the two-pass cold rolling, the Goss orientation significantly transformes into 111〈112〉 orientation, and this transformation becomes more complete with increasing reduction rate and strip thinning. Subsequently, after high-temperature annealing at different temperatures, the 111〈112〉 orientation texture transformes back into Goss110〈001〉. As the annealing temperature increases, grain size gradually grows, and both the proportion of Goss texture and the magnetic properties show an upward trend. Under higher annealing temperatures, the comprehensive magnetic properties of the ultra-thin grain-oriented silicon steel are better. When the annealing temperature reaches 940 ℃, the magnetic induction B₈₀₀ reaches 1.725 T, and the iron loss P_1.5/400 is 15.76 W/kg, achieving the best comprehensive magnetic performance under the experimental conditions.