Physical changes of silicon steel during annealing in annealing furnace

The annealing time is 60-210 min at 1000 ℃, and the average grain size of the annealed sample is about 187 μ m, which falls into the range of the best iron loss size (100-200 μ m). The Si concentration distribution of the samples annealed at 1000 ℃ for 210 Min has been homogenized.

Annealing at higher temperature and prolonging annealing time can reduce the surface texture density and increase the surface texture of silicon steel, and obtain the Gauss texture with density of 6.4. Annealing temperature and time have little effect on magnetic induction strength of silicon steel, while annealing time has great effect on iron loss. When the annealing time is fixed, the change of magnetic induction intensity is not obvious with the increase of annealing temperature, and the iron loss decreases gradually; when the annealing temperature is fixed, the iron loss decreases obviously with the extension of annealing time; when the annealing temperature is 1000 ℃ and the annealing time is 210 min, the iron loss is low and the magnetic induction intensity is high.

With the increase of annealing temperature, the content of magnetizable texture increases. The reason is that a large number of {111} surface textures are formed in silicon steel after cold rolling. During annealing, the recrystallized nuclei nucleate preferentially at the position with high storage energy, and devour the surrounding texture components, forming the texture grains with superior magnetic properties. These factors make the sample contain a lot of surface texture and improve the magnetic properties of the material. It can be seen from table 3 that the iron loss decreases gradually with the increase of annealing temperature, and the magnetic induction intensity changes little. Therefore, when the annealing time is prolonged at a higher temperature, the samples with larger grain size, {increased surface texture density and significantly reduced surface texture density can be obtained. The magnetic induction strength increases and the iron loss decreases obviously.