Introduction To Silicon Steel

A silicon alloy steel containing 1.0 to 4.5% of silicon and having a carbon content of less than 0.08% is called silicon steel. It has high magnetic permeability, low coercive force and large resistivity, so the hysteresis loss and eddy current loss are small. Mainly used as magnetic materials in motors, transformers, electrical appliances and electrical instruments. In order to meet the needs of punching and shearing processing in the manufacture of electrical appliances, it is also required to have a certain degree of plasticity. In order to improve the magnetic induction performance and reduce the hysteresis loss, it is required that the content of harmful impurities is as low as possible, and the plate type is required to be flat and the surface quality is good.

Performance characteristics

Silicon steel has core loss and magnetic induction as the magnetic guarantee value of the product. The loss of silicon steel can save a lot of power, extend the working hours of the motor and transformer and simplify the cooling system. The loss of electricity caused by silicon steel damage accounts for 2.5% to 4.5% of the annual power generation, of which transformer iron loss accounts for about 50%, 1-100kW small motors account for about 30%, and fluorescent lamp ballasts account for about 15%.

Silicon steel has a high magnetic induction, and the excitation current of the iron core is reduced, which also saves electric energy. The high magnetic induction of silicon steel can make the design with the highest magnetic induction (Bm), small core volume and light weight, saving silicon steel, wires, insulating materials and structural materials, which can reduce the loss of motor and transformer and manufacturing cost, and facilitate assembly. And transportation. A motor that is stacked with a toothed circular punch into a core operates in operation. Silicon steel sheets are required to be magnetically isotropic and made of non-oriented silicon steel. A transformer in which a strip is laminated into an iron core or wound into a core by a strip is operated in a stationary state, and is made of cold-rolled oriented silicon steel having a large magnetic anisotropy. In addition, silicon steel is required to have good punching property, smooth surface and uniform thickness, good insulating film and small magnetic aging.

Performance requirements

The requirements for the performance of silicon steel are mainly:

1. Low iron loss, which is the most important indicator of the quality of silicon steel sheet. Countries are divided according to the iron loss value, the lower the iron loss, the higher the grade.

2. The magnetic induction intensity is high under a strong magnetic field, which reduces the volume and weight of the iron core of the motor and the transformer, and saves silicon steel sheets, copper wires and insulating materials.

3. The surface is smooth, flat and uniform in thickness, which can improve the filling factor of the iron core.

4. good punching, is more important for the manufacture of miniature, small motors.

5. The surface insulating film has good adhesion and weldability, and can prevent corrosion and improve chipping property.

Production Process

Pickling

The oxide of the hot rolled steel strip is removed by a descaler and a hydrochloric acid tank to prevent defects on the surface of the cold rolled product.

Cold stamping

In order to ensure the thickness and material of different applications, the deceleration ratio is set at 40%-90%, and advanced control equipment such as automatic thickness control and automatic shape control is realized.

Annealing

It is a project to soften the hardened steel strip material in the cold stamping project. Through metal heating and rapid cooling, deep processing steel and high tensile steel are produced, and box annealing and continuous annealing are adopted.

Insulating coating

When the silicon steel sheet is processed into an iron core, in order to improve the processability and prevent the eddy current loss corresponding to the self-satisfaction of the thickness of the steel sheet, a continuous coating apparatus is used to spray the insulating coating liquid on the upper and lower sides of the steel sheet.

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