Evolution of microstructure and texture of ultra-thin non-oriented electrical steel manufactured by CSP

摘要

The evolution of the microstructure and texture of CSP thin-gauge non-oriented silicon steel was investigated by OM, XRD and EBSD. Results show: (1) the equiaxed surface grains with 28.13 mu m average grains size accounted for 19.14 of through-thickness, while deformed band structure dominated the center layer and the other maintained at a composite structure with the first two. With the cold-rolled reduction rate enhancing to 91.15, the stratification structure transformed into a complete fibrous structure. Annealing from 925 degrees C to 975 degrees C, the average grain size of the annealing plate similarly increased, which begins with 67.3 mu m and ends at 80.58 mu m. (2) The texture of the hot-rolled sheets mainly located at Cube and Goss texture, while with the cold-rolled process executing, the type and volume of texture change and finally stabilize at alpha fiber texture ({110}//RD) with the peak at {114} at 91.15 reductions rate. The {411} texture on the alpha* fiber line throughout maintained the strongest texture at different annealing temperatures. (3) The initial re-crystallization temperature is in the range of 600-620 degrees C, and the re-crystallization is roughly completed at 700 degrees C. Part of {411} oriented grains nucleated at {411} sub-grains originated from alpha fiber deformed structure, and the others nucleate at the grains boundaries of the deformed alpha fiber grains or in the inner of {111} and {111} grains. When the re-crystallization was accomplished at 750 degrees C, {411} oriented grains are significantly larger than other oriented grains compared to 680 degrees C or the less. (4) Best magnetic properties were obtained at 975 degrees C with the B-50 = 1.506 T and P-10/400 = 16.19 W/kg.