Three-phase EI laminatIion raw materials and processes

- Apr 09, 2019-

Three-phase EI lamination is made of silicon steel as a raw material. Silicon steel is a ferrosilicon alloy containing about 3% to 5% silicon and other iron. It is an important soft magnetic alloy that is indispensable in the power, electronics and military industries. It is also the most productive metal functional material, mainly used as the core of various motors, generators and transformers. 

The manufacturing technology and product quality of three-phase EI lamination is one of the important indicators to measure the level of special steel production and technology development in a country. In three-phase EI lamination, silicon is a good deoxidizer for steel, which combines with oxygen to convert oxygen into stable SiO2 that is not carbon-reduced, avoiding lattice distortion of iron due to oxygen atom doping. Silicon becomes a solid solution in alpha iron, which increases the electrical resistivity and helps to separate harmful impurities. 

Therefore, generally, iron containing impurities can increase magnetic permeability, reduce coercive force and iron loss when added to silicon. However, the increase in silicon content will make the material hard and brittle, and the thermal conductivity and toughness will decrease, which is unfavorable for heat dissipation and mechanical processing. Therefore, the silicon content of the silicon steel sheet generally does not exceed 4.5%. The three-phase EI laminatIion is divided into cold rolling and hot rolling, and most of the used ones are cold rolled silicon steel sheets. 

The cold-rolled three-phase EI laminatIion has excellent magnetic properties along the rolling direction, and has high saturation magnetic flux density and low iron loss in a strong magnetic field, and good magnetic properties in a weak magnetic field (initial magnetic permeability is large). This is because the cold rolling process reduces the impurity content in the steel sheet and causes coarse grains in the steel sheet, resulting in an increase in magnetic permeability and a decrease in hysteresis loss.