Basic knowledge of silicon steel (meaning, classification, grade representation, coating)

Basic knowledge of silicon steel (meaning, classification, grade representation, coating)

 

Silicon steel
silicon steel
Fe-si alloy with silicon content of 0.5%~4.8%. It is a soft magnetic material widely used in electrical field. Electrical silicon steel is often rolled into a standard size of large sheet or strip, commonly known as silicon steel sheet, widely used in motors, generators, transformers, electromagnetic mechanisms, relays electronic devices and measuring instruments.

Silicon is a good deoxidizer of steel, which combines with oxygen to transform oxygen into stable SiO2 that is not reduced by carbon, and avoids the lattice distortion of iron due to oxygen atom doping. When silicon becomes a solid solution in alpha iron, it increases the electropositive rate and helps to separate out the harmful impurities carbon. Therefore, generally containing impurities after the addition of silicon can improve the permeability, reduce coercivity and iron loss. However, the increase in silicon content will make the material hard and brittle, the thermal conductivity and toughness decline, which is unfavorable to heat dissipation and mechanical processing, so the silicon content of the general silicon steel sheet does not exceed 4.5%.

The silicon steel sheet is divided into cold rolling and hot rolling, and the most used is cold rolling silicon steel sheet. The cold-rolled silicon steel sheet has excellent magnetic properties along the rolling direction, not only has high saturation magnetic flux density and low iron loss in the strong magnetic field, but also has good magnetic properties in the weak magnetic field (large initial permeability). This is because the cold rolling process reduces the content of impurities in the steel sheet, and causes coarse grains in the steel sheet, resulting in an increase in permeability and a decrease in hysteresis loss.