Electrical steel is generally used to make original components of motors and transformers. Motors, transformers and other electrical components are generally required to have high efficiency, low power consumption, small size and light weight. Electrical steel plates usually use core loss and magnetic induction intensity as the guaranteed magnetic properties of the product. The performance requirements for electrical steel plates are as follows.
High magnetic induction intensity
Magnetic induction intensity is the number of magnetic field lines passing through the iron core per unit cross-sectional area, also called magnetic flux density. It represents the magnetizing ability of the material, and its unit is T. The iron core mass generally accounts for about 1/3 of the total mass of the motor and transformer. The magnetic induction intensity of the electrical steel plate is high, the excitation current (also called no-load current) of the iron core is reduced, and the copper loss and iron loss are reduced, which can save electric energy. When the electric energy of the motor and transformer remains unchanged, the magnetic induction intensity is high, the design Bm can be increased, and the cross-sectional area of the iron core can be reduced, which reduces the volume and mass of the iron core and saves the amount of electrical steel plates, wires, insulating materials and structural materials. , thus reducing the total losses and manufacturing costs of motors and transformers, and facilitating the manufacturing, installation and transportation of large transformers and large motors.
The magnetization curve of grain-oriented silicon steel along the rolling direction is very steep, and its bending point is significantly increased. The selected design Bm is as high as 1.7~1.8T, which is close to the B8 value, so B8 is used as the guaranteed magnetic induction value. The B8 value of oriented silicon steel along the rolling direction is more than 30% higher than the average B8 value of non-oriented silicon steel in the longitudinal and transverse directions, and the volume and mass of the made transformer core are correspondingly reduced by more than 30%. The motor design Bm is about 1.5T, which is close to the B50 value of cold-rolled non-oriented electrical steel, so B50 is used as the guaranteed value. The magnetic induction of hot-rolled silicon steel is lower, and B25 is often used as a guaranteed value.
