Evolution On The Microstructure And Texture Of High-grade Non-oriented Silicon Steels Prepared By Twin-Roll Casting Process

As important magnetic steel, silicon steels are widely used by electricity and electronics industries, mainly by manufacture generators, motors, transformers, transformers, relays and other electrical instruments. In this paper,4.5%Si non-oriented silicon steel with self-designed chemical component is used as experimental material, and 2mm cast strip is made by means of two roll casting. The structure, texture and precipitates in different sections are studied by means of OM, TEM, EPMA, EBSD, XRD. Results are as follows:(1) Precipitates in the cast strip are mainly AlN with typical polygon shape. The low content of Si limited the precipitation of MnS extremely. However, precipitates are observed to precipitate the complexes.(2) With increasing deformation, a, y-oriented online texture gradually become stronger, and the{001} plane texture increases with the reduction to the typical cube and rotate cube texture changes with increased strength. At the same time, comparing with the same cold rolling reduction ratio, y texture intensity was higher than the surface of the core layer. Hot rolling and cold rolling reduction rate increased with the alignment line a significantly enhanced texture. Textured surface y did not change significantly, and the center layer texture y increases significantly with the amount of deformation becoming stronger.(3) In either variant,the strength a, y texture after annealing weakened or even disappear, and the main types of texture to the ideal cube texture and rotating cube texture changes.(4) Compreing with four different rolling conditions, the B50 and B25 value reached the largest at 82.5% reduction, while the P15/50 reached the minimum at 50% hot rolling and 32.5% cold rolling. The iron loss of P10/400 and P5/1000 reached the minimum at the reduction rate of 82.5%.By comparison, the optimal magnetic properties in the cold rolling reduction rate was 82.5%.(5) When annealed at different temperatures, recrystallized grain nucleation priority in shear zones. While the shear zone consumed, the new grain nucleation transferred from shear zone to the deformation occurred in the crystalline grains.(6) Annealing from 600℃ to 1100℃, the magnetic induction intensity increases with the increase of annealing temperature, and the iron loss values decrease monotonously with the annealing temperature. Annealing at different times at the temperature of 700℃,with time prolonging, recrystallized grains gradually replaced the deformed grains, grain size uniformed gradually, the magnetic domain motion resistance decreases, and the iron loss minish.