① Low iron loss, which is the most important indicator of the quality of silicon steel sheets. Countries all classify grades according to the iron loss value. The lower the iron loss, the higher the grade.
② The magnetic induction intensity (magnetic induction) is high under a strong magnetic field, which reduces the volume and weight of the cores of motors and transformers, saving silicon steel sheets, copper wires, and insulating materials.
③The surface is smooth, flat and uniform in thickness, which can improve the filling factor of the core.
④Good punching performance and easy processing.
⑤The surface insulating film has good adhesion and weldability, can prevent corrosion and improve punching properties.
⑥Basically no magnetic aging.
Classification and brand definition of silicon steel sheets
Transformers usually use cold-rolled oriented silicon steel sheets to ensure their no-load energy efficiency levels. According to performance and processing methods, cold-rolled oriented silicon steel sheets can be divided into ordinary cold-rolled oriented silicon steel sheets, high magnetic permeability silicon steel sheets (or high magnetic susceptibility silicon steel sheets), and laser-marked silicon steel sheets. Usually, the silicon steel sheet with the minimum magnetic polarization intensity B800A=1.78T~1.85T achieved by the core under 50Hz, 800A alternating magnetic field (peak value) is called ordinary silicon steel sheet, recorded as "CGO", and B800A=1.85T or above The silicon steel sheet is recorded as a high magnetic permeability silicon steel sheet (high magnetic sensitivity silicon steel sheet) and is recorded as "Hi-B steel". The main difference between Hi-B steel and conventional silicon steel sheets is: the Gaussian azimuthal texture of Hi-B steel The degree of alignment is very high, that is, the silicon steel grains in the easy magnetization direction have a very high degree of alignment. Industrially, a secondary recrystallization process is used to manufacture silicon steel sheets with a silicon content of 3%. The grain orientation of Hi-B steel The average deviation from the rolling direction is 3°, while that of ordinary silicon steel sheets is 7°, which makes Hi-B steel have higher magnetic permeability. Usually its B800A can reach more than 1.88T, which improves the Gaussian azimuthal texture and Magnetic permeability reduces iron losses. Another feature of Hi-B steel is that the elastic tension of the glass film and insulating coating attached to the surface of the steel sheet is 3~5N/mm², which is better than the 1~2 N/mm² of ordinary oriented silicon steel sheets. The high-tension layer reduces magnetic domain width and reduces abnormal eddy current losses. Therefore, Hi-B steel has a lower iron loss value than conventional oriented silicon steel sheets.
Laser-marked silicon steel sheets are based on Hi-B steel and use laser beam irradiation technology to produce tiny strains on the surface, further refining the magnetic axis and achieving lower iron loss. Laser-marked silicon steel sheets cannot be annealed because the laser treatment effect will disappear if the temperature is increased.
The physical properties of silicon steel sheets of different grades are basically the same, and the density is basically 7.65g/cm³. For the same type of silicon steel sheets, the main difference in performance and quality is the silicon content and the influence of the production process.