Go Electrical Steel-Jinhongtong Group Co., Ltd.

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Go Electrical Steel

Silicon Steel

Silicon steel, also known as electrical steel, silicon electrical steel, lamination steel, relay steel, or transformer steel is specialty steel with silicon added to it, which improves its electrical resistivity and magnetic properties, and reduces hysteresis loss. This steel is ideal for various electrical applications where electromagnetic fields are important, such as transformers, magnetic coils, and electrical motors.

Electrical steel usually referred to as cold-rolled electrical steel, can be divided into two major categories including grain-oriented electrical steel and non-oriented electrical steel. Grain-oriented electrical steel, with its easy magnetization direction parallel to the rolling direction, has excellent magnetic properties in this direction including low core loss, high permeability, and low magnetostriction, and is widely used in the transformer industry. Further, it can obtain lower core loss by domain refinement treatment. Meanwhile, non-oriented electrical steel, featured by a random distribution of grain orientation and magnetic isotropy, is widely applicable to the motor industry.

Product Specification and Size :

Standard Size

Thickness	Width	Slitting	Inside Diameter	Outside Diameter
0.35mm, 0.50mm, 0.65mm	Original: 750~1290mm	40~645mm	508~610mm	800~1550mm

Silicon Steels and Their Applications

Silicon steel is the most important magnetic material in industrial applications. The general applications include volt relays or pulse transformers from the generator, automotive, and transformer sectors.

Silicon steel is undoubtedly the most important soft magnetic material in use today. Applications vary in quantities from the few ounces used in small relays or pulse transformers to tons used in generators, motors, and transformers. Continued growth in electrical power generation has required development of better steels to decrease wasteful dissipation of energy (as heat) in electrical apparatus and to minimize the physical dimensions of the increasingly powerful equipment now demanded.

Substantial quantities of oriented steel are used, mainly in power and distribution transformers. However, it has not supplanted nonoriented silicon steel, which is used extensively where a low-cost, low-loss material is needed, particularly in rotating equipment. Mention should also be made of the relay steels, used widely in relays, armatures, and solenoids. Relay steels contain 1.25 to 2.5% Si, and are used in direct current applications because of better permeability, lower coercive force, and freedom from aging.

Important physical properties of silicon steels include resistivity, saturation induction, magneto-crystalline anisotropy, magnetostriction, and Curie temperature.

Applications for oriented silicon steel include transformers (power, distribution, ballast, instrument, audio, and specialty), and generators for steam turbine and water wheels.

Fields of Application

Fields of application		Grain-oriented electrical steel			Non-oriented electrical steel
		Series G	Series P	Series R	Series A			Series AH		Series AR	Series AT
		Series G	Series P	Series R	230~400	440~700	800~1300	230~470	600~1000	Series AR	Series AT
Rotators	Large-sized motors	√			√
	Medium-sized motors				√	√		√
	Compressor motors				√	√	√	√	√	√
	General motors				√	√	√	√	√	√
	Small-sized precision motors				√	√	√	√		√	√
	Motors for electric cars				√			√		√	√
Static device	High-frequency motors				√			√			√
	Large-sized transformers	√	√	√
	Small-sized power transformers	√	√	√	√	√	√	√	√	√
	Transformers for instruments	√	√		√
	Reactors and magnetic amplifiers	√	√	√	√
	Power switches				√
	Transformers for welding					√	√		√
	Voltage regulators				√	√	√	√	√	√
	Magnetic sealers	√	√		√	√
	Electromagnetic devices for accelerators	√	√			√		√

-Material Selection

Grain-oriented electrical steel


Varieties	Common type	High induction type	Domain refinedhigh induction type
Large motors	√	√
Large transformers	√	√	√
Medium and small transformers	√	√	√
Distributing transformers	√	√
Voltage regulator	√	√	√
Reactor and magnetic amplifier	√	√
IF transformer		√
Mutual inductor	√	√
TV transformer	√	√
Radio transformer	√	√
Radio broadcast transformer		√

Mechanical Property

Mechanical Property
Grade	Yeild Strength(N/mm2)	Ultra-TensionStrength(N/mm2)	Ductility(%)	Hardness(HV1
M35W230	430	560	20.0	225
M35W250	415	550	20.5	220
M35W270	400	515	20.5	215
M35W300	360	480	21.5	195
M35W360	350	480	23.5	190
M35W440	275	420	27.5	165
M35W550	265	415	33.5	160
M50W250	430	560	19.0	230
M50W270	410	550	21.5	225
M50W290	395	545	22.5	220
M50W310	385	510	24.5	210
M50W350	350	475	26.5	190
M50W400	320	460	36.0	170
M50W470	295	425	35.0	160
M50W600	280	410	37.0	140
M50W800	285	405	38.5	135
M50W1300(D)	250	360	40.0	115

Insulating Coating

Insulating Coating
Coating types	M11	M21
Component	Chromium containing , semi organic coating	Chromium free, semi organic coating
Coating thickness(μm)	0.7~1.5	0.8~5.0
Interlayer resistance(Ω•mm2 /slice)	≥100	≥100
Adhesive property	Class A or class B	Class A or class B
Punching property	Excellent	Excellent
Antirust property	Excellent	Excellent
Heat resisting property	Resistant annealing at 750 C, N2 protection, for 2h	Annealing resistance in general

Making and Using Oriented Steel

Oriented silicon steel is more restricted in composition than non-oriented varieties. The texture is developed by a series of careful working and annealing operations, and the material must remain essentially single-phase throughout processing, particularly during the final anneal because phase transformation destroys the texture. To avoid the y loop of the Fe-Si phase system, today`s commercial steel has about 3.25% Si. Higher silicon varieties, which might be favored on the basis of increased resistivity and lower magnetostriction, are precluded by difficulties in cold rolling.

Temperature, atmosphere composition, and dew point are closely controlled to decarburize the strip without oxidizing the surface. During this treatment, primary recrystallization occurs, forming small, uniform, equiaxed grains. The coating of magnesium silicate glass which forms will provide electrical insulation between successive laminations when assembled in a transformer core. At this stage, the steel is graded by cutting Epstein samples from the coil; the samples are stress relief annealed and flattened at 790°C, and tested for core loss.

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