Introduction to Silicon Steel

Silicon steel contains 1.0-4.5% silicon, and silicon alloy steel with a carbon content less than 0.08% is called silicon steel. The lower the iron loss value, the better the quality of iron; The weight of a typical silicon steel coil is around 3-4 tons. It has characteristics such as high permeability and high resistance coefficient, so both 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 when manufacturing electrical appliances, a certain degree of plasticity is also required. In order to improve magnetic induction performance and reduce hysteresis loss, it is required that the lower the harmful impurity content, the better, and that the plate shape is flat and the surface quality is good. Silicon steel uses iron core loss (referred to as iron loss) and magnetic induction strength (referred to as magnetic induction) as the magnetic guarantee values of the product.

Electrical steel is divided into two types: hot-rolled and cold-rolled. Cold rolled electrical steel is divided into oriented electrical steel and non oriented electrical steel based on the orientation of internal grains. The grains of oriented electrical steel are generally oriented in one direction, with a high silicon content, and are mainly used in transformer manufacturing; Non oriented electrical steel has a disorderly grain distribution and low silicon content, mainly used in motor manufacturing.

Low iron loss of silicon steel can save a lot of electricity, prolong the operating time of motors and transformers, and simplify the cooling system. The power loss caused by silicon steel iron loss 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%.

The main requirements for the performance of silicon steel are: 1. Low iron loss, which is the most important indicator of the quality of silicon steel sheets. Various countries classify grades based on iron loss values, with the lower the iron loss, the higher the grade.

2. Under strong magnetic fields, the magnetic induction intensity (magnetic induction) is high, which reduces the volume and weight of the iron core of the motor and transformer, saving silicon steel sheets, copper wires, and insulation materials.

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

4. Good lamination performance is more important for manufacturing micro and small electric motors.

5. The adhesion and weldability of the surface insulation film are good, which can prevent corrosion and improve the punching performance.