57일차. 실리콘 스틸(Silicon Steel)이란?

 

What Is Silicon Steel？; 실리콘 스틸이란？.pdf

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실리콘 스틸이란?
전기 강철이라고도 하는 실리콘 강철은 실리콘이 첨가된 강철입니다. 규소를 강철에 첨가하면 전기 저항이 증가하고 자기장이 침투하는 능력이 향상되며 강철의 히스테리시스 손실이 줄어 듭니다. 실리콘 강철은 변압기, 자기 코일 및 전기 모터와 같이 전자기장이 중요한 많은 전기 응용 분야에 사용됩니다.

실리콘 스틸의 실리콘은 그 안에 철의 부식 속도를 감소시킬 수 있지만, 실리콘을 추가하는 주요 목적은 스틸의 히스테리시스 손실을 개선하는 것입니다. 히스테리시스는 자기장이 처음 생성되거나 강철에 적용되는 시간과 자기장이 완전히 발달 할 때까지의 지연입니다. 강철에 실리콘을 첨가하면 자기장을 만들고 유지하는 측면에서 강철을 보다 효율적이고 빠르게 만들 수 있습니다. 따라서, 실리콘 스틸은 스틸을 자성 코어 재료로 사용하는 모든 장치의 효율성과 효과를 향상시킵니다.

실리콘 강에 첨가된 실리콘의 비율은 의도된 사용에 따라 6.5%까지 다양합니다. 고효율 모터 및 변압기와 같은 일부 품목의 경우 실리콘은 강철 구성의 약 3%를 구성합니다. 특정 유형의 모터 응용 분야와 같이 효율성이 더 낮은 다른 항목에서는 실리콘의 양이 2% 정도로 낮을 수 있습니다. 일반 탄소강과 비교할 때 비싸지만 특정 용도에 필요한 비율의 실리콘으로 실리콘 강을 생산할 수 있습니다.

 

규소 강은 스트립 또는 롤 형태로 생산되며, 필요한 형상으로 절단된 후 열처리되어 강 입자의 크기를 제어합니다. 입자 크기의 제어를 통해 강의 히스테리시스 손실을 정확하게 제어 할 수 있습니다. 규소 강의 입자 방향 또한 효율에 영향을 줄 수 있습니다. 그레인은 밀도를 향상시키기 위해 롤링을 통해 한 방향으로 배향 될 수 있거나, 그레인은 배향되지 않고 모든 방향으로 진행될 수 있어, 실리콘 스틸을 덜 비싸게 만든다.

열처리 공정이 완료되면, 실리콘 스틸은 종종 코팅 또는 니스 처리되어 부식을 더 지연시키고 필요한 두께로 적층됩니다. 이러한 두께를 라미네이션이라고하며 물리적으로 서로 부착되거나 결합되지 않을 수 있습니다. 이러한 적층형 라미네이션은 가전제품용 전원 어댑터에서 가정 및 기업에 전력을 공급하는 변전소 변압기에 이르기까지 현대의 거의 모든 전자기 장치의 핵심 역할을 합니다.

 

 

What Is Silicon Steel?

Silicon alloy steel containing 1.0 to 4.5% silicon and less than 0.08% carbon is called silicon steel. It has the characteristics of high magnetic permeability, low coercive force and large resistivity, so the hysteresis loss and eddy current loss are small. Mainly used as magnetic materials in motors, transformers, electrical appliances and electrical instruments. In order to meet the needs of punching and shearing when manufacturing electrical appliances, a certain degree of plasticity is also required. In order to improve the magnetic induction performance and reduce the hysteresis loss, the lower the content of harmful impurities, the better, and the flat shape and the good surface quality are required. [1]

 

In 1900, RA Hadfield reported that iron-silicon alloys with a silicon content of 2.5% to 5.5% had higher magnetic properties than iron. Production of hot rolled silicon steel sheets began in 1903. In 1934, GossNP developed (110) [001] cold-rolled oriented silicon steel, and its magnetic properties were significantly improved along the rolling direction of the steel plate. It is suitable for making transformers. In 1935, the American Armco Steel Company began production, and then again Production of cold-rolled non-oriented silicon steel. In 1949, Amco made 0.05mm and 0.1mm thick cold-rolled oriented silicon steel strips for military industry. In the early 1960s, the United States began mass production of low-carbon electrical steel with silicon content <0.5%. In the late 1960s, some countries ceased production of hot-rolled silicon steel. In 1968, Japan's Nippon Steel & Iron Corporation developed and produced Hi-B steel. In the mid-1970s, Japan successively developed several new grades of oriented silicon steel, non-oriented silicon steel, and low-carbon electrical steel. In 1986, Japan Steel Pipe Company produced high silicon steel products with a silicon content of 6.5%. China produced hot-rolled silicon steel in 1954, made and produced cold-rolled oriented silicon steel strips in 1959, and produced cold-rolled and non-oriented silicon steel in 1979. The annual output of electrical steel in the world is more than 6 million tons, accounting for 0.9% to 1.3% of the total steel output. The annual output of Japan, the former Soviet Union and the United States exceeds 1 million tons, of which oriented silicon steel accounts for about 25%, and low-carbon and low-silicon electrical steel accounts for about 65%.

Silicon steel uses iron core loss (abbreviated as iron loss) and magnetic induction strength (abbreviated as magnetic induction) as the guaranteed magnetic value of the product. Low silicon steel loss can save a lot of electricity, prolong the operating time of motors and transformers, and simplify the cooling system. Electricity loss due to silicon steel loss accounts for 2.5% to 4.5% of the annual power generation, of which transformer iron loss accounts for about 50%, 1-100kW small motors account for about 30%, and fluorescent lamp ballasts account for about 15%.

Silicon steel has a high magnetic induction, and the exciting current of the iron core is reduced, which also saves power. The high magnetic induction of silicon steel can make the designed maximum magnetic induction (B m ) high, the core size small, light weight, saving silicon steel, wires, insulating materials and structural materials, etc., which reduces the loss of motors and transformers and manufacturing costs, and facilitate Assembly and transportation. The motor with the iron cores formed by the toothed round punches works in the running state. The silicon steel plate is required to be magnetically isotropic and made of non-oriented silicon steel. Transformers that are laminated into cores from strips or wound into cores from strips work in a stationary state and are made of cold-rolled oriented silicon steel with large magnetic anisotropy. In addition, silicon steel is required to have good punching and shearing properties, smooth and flat surface and uniform thickness, and good insulation film and small magnetic aging.

According to the manufacturing process and application, electrical steel is divided into three categories: hot-rolled silicon steel, cold-rolled electrical steel and special-purpose silicon steel. The silicon content, specifications and main uses are shown in Table 1.

 

Table 1 Classification and application of electrical steel

The requirements for the properties of silicon steel are:

1. Low iron loss, which is the most important indicator of the quality of silicon steel sheet. Each country divides the grade according to the iron loss value. The lower the iron loss, the higher the grade.

 

2. High magnetic induction strength (magnetic induction) under strong magnetic field, which reduces the volume and weight of the iron core of the motor and transformer, saving silicon steel sheets, copper wires and insulation materials.

 

3. The surface is smooth, flat and uniform in thickness, which can improve the filling factor of the iron core.

 

4. Good punching performance is more important for manufacturing miniature and small motors.

 

5. The surface insulation film has good adhesion and weldability, which can prevent corrosion and improve punchability.

 

 

Silicon steel pickling

The scale descaler and the hydrochloric acid tank are used to remove the oxide of the hot-rolled steel strip to prevent defects on the surface of the cold-rolled product.

 

 

Silicon steel cold stamping

In order to ensure the thickness and material of different applications, the reduction ratio is set at 40% -90%, and advanced control equipment such as automatic thickness control and automatic shape control are implemented.

 

 

Silicon steel annealing

It is a process to soften the hardened steel strip material in the cold stamping process. Through metal heating and rapid cooling, deep-processing steel and high-tensile steel are produced, and boxing (shrouding) annealing and continuous annealing methods are used.

 

 

Silicon steel insulation coating

When a silicon steel sheet is processed into an iron core, in order to improve its workability and prevent eddy current loss equivalent to the thickness of the steel sheet, continuous coating equipment is used to spray insulating coating liquid on the top and bottom of the steel sheet. [2]