Cold Rolled Electrical Steel

Cold Rolled Electrical Steel Product Description

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The contents of elements such as silicon, aluminum and manganese in the steel need to be controlled within a certain range as required, and the impurity contents such as carbon, sulfur, nitrogen and oxygen should be as low as possible. With the increase of the grade, the silicon content can be increased to about 3% and remains unchanged, and the aluminum content can be gradually increased to 1%. The aluminum content of general grades is 0.3% – 0.6%. At the same time, the contents of carbon, sulfur and manganese in high-grade grades will be further reduced.

 

For example, the impurity content requirements for high grades are: S < 0.002%, C < 0.003%, N₂ < 0.002%, O₂ < 0.002%, so that decarbonization is not required during subsequent annealing to prevent the formation of internal oxide and nitride layers. In addition, it is usually also required that Ti < 0.005% and Zr < 0.002% to avoid the formation of fine TiN, ZrN and TiC that hinder grain growth.

 

Process Flow

 

Non-oriented silicon steel characteristics:

• Low iron loss: This is an important indicator of quality. Countries around the world usually classify grades based on iron loss values. The lower the iron loss, the higher the grade and the better the quality.

 

• High magnetic induction intensity: Silicon steel sheets that can obtain higher magnetic induction under the same magnetic field. The volume and weight of the motor or transformer core manufactured with it are smaller, and relatively, silicon steel sheets, copper wires and insulating materials can be saved.

 

• High stacking factor: The surface of the silicon steel sheet is smooth, flat and uniform in thickness, which can increase the stacking factor for manufacturing the core.

 

• Good punching property: This is particularly important for manufacturing small and micro motor cores.

 

• Good adhesion and weldability of the surface to the insulating film: It can play a role in preventing corrosion and improving the punching property.

 

• Low magnetic aging phenomenon.

 

Aspects of Difference Between Grain-oriented silicon and Non-oriented

Magnetism:Grain-oriented silicon steel has high magnetic permeability and low iron loss along a specific direction, with strong directionality.
Non-oriented silicon steel has relatively uniform magnetism in all directions, and its magnetic performance is slightly poorer.

Usage:Grain-oriented silicon steel is used in transformers because of its excellent magnetic performance in a specific direction, which can improve energy efficiency and reduce volume.

Non-oriented silicon steel is used in motors. The magnetic field of the motor is complex, and the requirement for the magnetic direction is low.

Manufacturing process:The manufacturing process of grain-oriented silicon steel is complex, requiring high-temperature annealing and special coatings to achieve good orientation.

The process of non-oriented silicon steel is relatively simple.

Price:Grain-oriented silicon steel has excellent performance and a complex process, and the price is high.

 

Take large power transformers as an example. To ensure efficient energy transmission and reduce volume, grain-oriented silicon steel is often selected. In industrial motors, due to the complex magnetic field, non-oriented silicon steel is more applicable and has a lower cost.

 

Cold Rolled Electrical Steel specifications

Category			Silicon Content/%	Nominal Thickness/Mm	Lord To Use Way
Hot Rolled Silicon Steel (No Orientation)	Hot rolled low silicon steel(Motor Steel)		1.0~2.5	0.5	Household motors and micromotors
	Hot rolled high silicon steel(Transformer steel)		3.0~4.5	0.35,0.50	Transformer
Cold Rolled Electrical Steel	Cold rolled non-oriented electrical steel(Motor Steel)	Low carbon electrical steel	≤ 0.5	0.50,0.65	Small transformers and ballasts for household motors, micromotors
		Silicon steel	>0.5~3.5	0.35,0.50	Medium and large motors, generators and transformers
	Cold rolled grain oriented silicon steel(Transformer steel)	Ordinary oriented silicon steel	2.9~3.3	0.18,0.23,0.27 0.30,0.35	Large, medium and small transformers and ballasts
		High magnetic induction oriented silicon steel
Special Purpose Silicon Steel	Cold rolled grain oriented silicon steel strip		2.9~3.3	0.03,0.05,0.10	Pulse transformer, magnetic amplifier, high frequency transformer and electric welding machine
	Cold rolled non-oriented silicon steel strip		3.0	0.15,0.20	High-frequency motors and generators
	Cold rolled non-oriented silicon steel for magnetic switch		3.0	0.70	Relays and magnetic switches
	Cold rolled high silicon steel		6.5	0.1~0.5	High-frequency motors, transformers and magnetic shielding