Silicon steel sheet

Silicon steel definition
Silicon steel, also known as silicon steel, is an iron-silicon alloy developed on the basis of industrial pure iron. It is an important soft magnetic material, accounting for 90%-95% of the total magnetic materials. It is mainly used to make various motors and transformers. Iron core is an iron-silicon alloy with a carbon content (mass percentage) of less than 0.02% and a silicon content (mass percentage) of 1.5%-4.5%.

The solid solubility of silicon in iron at room temperature is about 15%. However, as the silicon content increases, the brittleness of the material increases, and the magnetic induction intensity decreases. Industrially, the silicon content of 5% is the upper limit of general silicon steel. Silicon steel sheet
In order to reduce eddy current losses, laminated silicon steel sheets are commonly used in industry to replace the entire silicon steel. Theoretically, the thinner the silicon steel sheets, the better, but it is subject to processing technology (silicon steel is brittle), heat dissipation, magnetic conductivity (proportion of insulation layer), cost, etc. Affected by factors, the thickness of commonly used silicon steel sheets is 0.2-0.5mm;

Silicon steel sheet classification
According to the production process, silicon steel sheets are divided into cold-rolled silicon steel sheets and hot-rolled silicon steel sheets: 1. Hot-rolled silicon steel sheet: The iron-silicon alloy is melted in an electric furnace, repeatedly hot-rolled into thin plates, and annealed at 800-850°C. The advantages are good stability, lower punching and shearing stress than cold rolling, and small specific gravity.

2. Cold-rolled silicon steel sheet: Iron-silicon alloy is melted in an electric furnace and made through hot rolling, normalization, cold rolling, annealing and secondary cold rolling. The advantages are high magnetic induction intensity, low iron loss, and lamination coefficient. higher.

According to the magnetization properties of silicon steel, silicon steel sheets are divided into non-oriented silicon steel sheets and oriented silicon steel sheets; the crystal structure of silicon steel is cubic, and each crystal has an easy magnetization axis and a difficult magnetization axis. Corresponding processes can be adopted in the process of making silicon steel sheets. Control the lattice distribution to obtain the corresponding silicon steel sheet.

1. Non-oriented silicon steel sheets: The crystals of silicon steel sheets are easily arranged in random directions along the magnetization axis, and the magnetism in each direction is not much different;

2. Oriented silicon steel sheet: The easy magnetization axis of the crystal lattice of the silicon steel sheet is parallel to the rolling direction, that is, it is easy to magnetize along the rolling direction. This kind of directional silicon steel sheet is called oriented silicon steel sheet; the production process of oriented silicon steel sheet is relatively non-oriented. It is complicated, and MnSe or MnS needs to be added to ensure the growth of secondary recrystallized grains.

Because when the motor is running, the iron core is made of laminated circular punched sheets with cogging, and the silicon steel sheets are required to be isotropic. Generally, the magnetic induction difference is required to be less than 10%, and the vertical and horizontal iron loss difference is less than 8%. Use no Oriented silicon steel; Cold-rolled silicon steel sheets have higher magnetic induction intensity and higher lamination coefficient than hot-rolled ones, so cold-rolled ones are preferred. Therefore, cold-rolled non-oriented silicon steel sheets are generally used in motors.