Views: 0 Author: Site Editor Publish Time: 2024-12-31 Origin: Site
There are many materials with magnetic conductivity, such as silicon steel, titanium base alloy, copper base alloy, iron strontium titanate, etc., these materials have good magnetic conductivity, why silicon steel stands out, and other materials have not become the first choice for transformer core materials?
Silicon steel has high permeability
Silicon steel has low iron loss, compared with other materials, its iron loss is much lower, which is one of the main reasons why silicon steel sheets become transformer core materials.
The hysteresis performance of silicon steel is better, and it can shake quickly under the action of magnetic field, so the hysteresis loss is much smaller than that of other materials.
The corrosion resistance of silicon steel is good, and it has high corrosion resistance to some chemical external environments.
The material cost is moderate, although the price of silicon steel sheet is relatively high, but considering its excellent performance and long service life, its cost effectiveness is still very high.
Silicon steel has a certain mechanical strength and can support the windings and other components of transformers.
The whole piece of silicon steel is thick, which brings a lot of "eddy current loss", and the silicon steel processed into sheets can reduce the iron loss of the transformer, that is, "eddy current loss". The iron core of the transformer is composed of silicon steel sheets insulated from each other, and the cross-sectional area of the sheet is small, so that the eddy current passes through a small cross-section in the narrow and long circuit, thereby increasing the resistance on the eddy current path and reducing the eddy current loss.
And the sheet manufacturing method is more flexible and easy to process. In the manufacturing process, high-quality silicon steel sheet materials can be selected, and precise cutting and processing can be performed according to the design requirements to maintain the thickness and flatness of the silicon steel sheet. This manufacturing method can save materials, reduce production costs, and improve the performance and reliability of the transformer.
According to the production process, it can be divided into cold-rolled silicon steel sheet and hot-rolled silicon steel sheet;
Cold-rolled silicon steel sheet: Cold-rolled silicon steel sheet is produced by rolling at room temperature, with smooth surface, no cracks, uniform density, and stable magnetic properties. According to the different silicon content, it is divided into ordinary type and high silicon type two.
Hot-rolled silicon steel sheet: hot-rolled silicon steel sheet is rolled to electrical steel at high temperature, the price is cheaper than cold-rolled silicon steel sheet, but the surface is not as smooth as cold-rolled silicon steel sheet, and the magnetic properties are slightly worse. Hot rolled silicon steel sheet is divided into ordinary type, high silicon type and ultra-high silicon type according to the different silicon content.
According to the direction of magnetization, it can be further classified into cold-rolled non-oriented silicon steel sheet, cold-rolled oriented silicon steel sheet and hot-rolled oriented silicon steel sheet.
Cold-rolled non-oriented silicon steel sheet: This silicon steel sheet is one of the most commonly used silicon steel sheets for the manufacture of transformers, its main characteristics are high permeability, low magnetic loss, suitable for the manufacture of a variety of small power transformers and inductors and some magnetic materials.
Cold-rolled oriented silicon steel sheet: this refers to the forced orientation of silicon steel sheet in the production process, the magnetization direction is perpendicular to the rolling direction, so that the magnetic flux direction is coincident with the core, so as to reduce the role of iron loss and magnetic loss. This kind of silicon steel sheet is widely used in high-power transformers and various motors.
Hot-rolled oriented silicon steel sheet: This is a relatively new silicon steel sheet, mainly used in high-end power industries such as high-power transformers, motors and frequency converters. Its magnetic properties are more superior than the other two silicon steel sheets, which can reduce iron loss and magnetic loss, and improve the magnetic flux and efficiency of the iron core.
The silicon steel sheet can be divided into EI type, UI type, C type, mouth type and so on according to the different shapes. Mouth silicon steel sheet is often used in transformers with large power, it has good insulation performance, easy heat dissipation, and short magnetic circuit.
Forging (black sheet), no forging (white sheet) : This is classified according to whether the silicon steel sheet has been insulated. After high temperature treatment, a layer of oxide film is formed on the surface of the forged silicon steel sheet to improve the insulation performance. The non-forged silicon steel sheet remains in its original state with a smooth surface.
It is precisely because of its unique properties that silicon steel sheet has become a common core material for transformers. Of course, transformers are not only this kind of core material, amorphous alloys are also used as core materials. However, its production process is relatively complex and the cost is high, and the commonly used material for transformer core is still silicon steel sheet.
