Introduction To Electrical Steel

GNEE ELECTRICAL STEEL

Electrical steel definition

Electrical steel, also known as silicon steel, is an important soft magnetic alloy indispensable in the power, electronics and military industries. It is also the metal functional material with the largest production volume. It is mainly used as the iron core of various motors, generators and transformers. Its production process is complex and the manufacturing technology is strict. Foreign production technologies are protected in the form of patents and are regarded as the life of the enterprise. The manufacturing technology and product quality of electrical steel plates are one of the important indicators to measure the level of special steel production and technological development of a country. At present, the quantity, quality, and specifications of cold-rolled electrical steel in my country cannot meet the needs of the development of the energy (power) industry. There is a certain gap compared with Japan in terms of production technology, equipment, management, and scientific research.
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Electrical Steel Overview

Electrical steel has a history of hundreds of years. Electrical steel includes electrical steel with Si <0.5% and silicon steel with Si content of 0.5~6.5%. It is mainly used as the core of various motors, transformers and ballasts. It is an important part of electric power, electronics and An important soft magnetic alloy that is indispensable in the military industry. Electrical steel is the largest used magnetic material and is also an important energy-saving metal functional material. The manufacturing process and equipment of electrical steel, especially oriented silicon steel, are complex, the composition is strictly controlled, the manufacturing process is long, and there are many factors that affect performance. Therefore, the quality of oriented silicon steel products is often regarded as an important indicator of a country's special steel manufacturing technology level. , and won the reputation of "art product" among special steels.

Electrical steel coil

Electrical steel performance requirements

Low core loss (PT): Core loss refers to the ineffective electric energy consumed when the core is magnetized under an alternating magnetic field of ≥50Hz, referred to as iron loss, also called alternating loss, and its unit is W/kg. This kind of ineffective electric energy consumed due to various obstacles to the change of magnetic flux not only loses electric energy through the heating of the iron core, but also causes the temperature rise of the motor and transformer. The iron loss (PT) of electrical steel includes three parts: hysteresis loss, eddy current loss (Pe) and abnormal loss (Pa). Electrical steel plates have low iron loss, which can not only save a lot of electrical energy, but also extend the operating time of motors and transformers, and simplify cooling devices. Since the power loss caused by the iron loss of electrical steel plates accounts for 2.5% to 4.5% of the annual power generation in various countries, countries producing electrical steel plates always try every means to reduce iron losses, and use iron loss as the most important indicator to evaluate the magnetic properties of products. The iron loss value of the product is used as the basis for classifying product brands.

Magnetic induction intensity (B) is high: Magnetic induction intensity is the number of magnetic force 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 the unit is T. 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 power 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 weight of the iron core and saves the amount of electrical steel plates, wires, insulation materials and structural materials. It can reduce the total loss and manufacturing cost of motors and transformers, and is beneficial to the manufacturing, installation and transportation of large transformers and large motors.

The design Bm of grain-oriented silicon steel is as high as 1.7~1.80T, which is close to the B8 value, so B8 is used as the guaranteed magnetic induction value. The design Bm of the motor is about 1.5T, which is close to the B50 value of cold-rolled non-oriented electrical steel. Therefore, B50 is used as the guaranteed magnetic induction value of cold-rolled non-oriented silicon steel. The magnetic induction of hot-rolled silicon steel is lower, and B25 is usually used as the guaranteed value.

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