Grain Oriented Silicon Steel

One-Stop Sourcing for High-Quality Grain-Oriented Silicon Steel

The main advantage of grain-oriented silicon steel is its excellent magnetic properties along the rolling direction. This comes from precise control of the Goss texture ({110}<001>). Key technical characteristics are listed below.

Low Core Loss – High-purity melting, proper inhibitors, and secondary recrystallization are used. Eddy current loss and hysteresis loss are greatly reduced. Core loss is much lower than non-oriented silicon steel. This minimizes heat generation and energy loss in transformers.

High Magnetic Induction – Magnetic polarization reaches over 1.88 T (at 800 A/m). The material carries higher magnetic flux density under the same excitation. This reduces transformer core size, weight, and cost.

Low Magnetostriction – The magnetostriction coefficient is effectively suppressed. Transformer cores vibrate less and produce lower noise at power frequency. This meets requirements for quiet urban power equipment.

Excellent Lamination Factor – Thickness tolerance is tight (within ±0.005 mm). Surfaces are smooth and flat. The stacking factor exceeds 0.96. This increases the effective magnetic circuit area.

Surface Insulation Coating – Phosphate or chromate based inorganic coatings (T1/T2/T3) are used. They provide interlayer insulation to reduce eddy current loss. They also offer good heat resistance, adhesion, and punchability. Some high-end products use laser or mechanical scribing to refine magnetic domains and further reduce loss.

In summary, grain-oriented silicon steel is irreplaceable for power and distribution transformer cores. This is due to the synergy of texture control, thin-gauge rolling, and advanced coatings.

1.The thickness and width of grain-oriented silicon steel

Grain-oriented silicon steel （GOES Steel） is mainly divided into conventional thickness and ultra-thin gauge categories. Conventional thickness products benefit from mature processing and wide master coils, making them suitable for high-volume transformer core production. Ultra-thin gauges, produced through more precise rolling, offer low core loss and are mainly used in medium-to-high frequency applications. Both categories can be further processed via slitting into narrow strips to meet various core size requirements. The detailed comparison is as follows:

Conventional Thickness

Thicknesses: 0.20 mm, 0.23 mm, 0.27 mm, 0.30 mm, 0.35 mm

Master coil width: 600 – 1250 mm

Width after slitting: Can be slit down to 20 – 600 mm (any narrow strip)

Applications: Power transformers and distribution transformers at power frequency (50/60 Hz)

Ultra-Thin Gauge

Thicknesses: 0.15 mm, 0.10 mm, 0.08 mm, 0.05 mm (listed from thicker to thinner)

Master coil width: 100 – 500 mm

Width after slitting: Can be slit down to 10 – 300 mm narrow strips

Applications: Medium-to-high frequency transformers, pulse transformers, magnetic amplifiers

Key Comparison

Conventional thickness → Wide master coils + flexible slitting → balances productivity and dimensional adaptability

Ultra-thin gauge → Narrower master coils + even narrower slitting → trades width for ultra-low core loss at medium/high frequencies

Iron Loss and Magnetic Induction of Grain-Oriented Silicon Steel

\ \ \ Typical magnetic properties of major grain-oriented electrical steel grades of Baosteel
Type	Grade	Specific total loss(W/kg)		Magnetic polarization (T)	Exciting power(VA/kg)
Type	Grade	P_1.5/50	P_1.7/50	J₈₀₀	Ss_1.7/50
Conventional Grades	B23G110	0.71	0.99	1.89	1.85
	B27G120	0.76	1.04	1.89	1.90
	B30G120	0.79	1.08	1.89	1.90
	B35G135	0.90	1.18	1.89	1.71
High Permeability Grades	B18P080	0.58	0.79	1.89	1.48
	B20P080	0.59	0.79	1.89	1.34
	B23P085	0.62	0.83	1.92	1.20
	B27P095	0.68	0.92	1.91	1.34
	B27P100	0.69	0.94	1.91	1.42
	B30P105	0.74	0.99	1.91	1.41
	B30P120	0.76	1.02	1.91	1.52
Domain Refined High Permeability Grades	B18R065	0.48	0.64	1.91	1.91
	B20R070	0.51	0.68	1.91	1.96
	B23R075	0.56	0.74	1.92	1.65
	B23R080	0.57	0.77	1.91	1.86
	B23R085	0.59	0.80	1.91	2.10
	B27R085	0.62	0.82	1.91	1.82
	B27R090	0.64	0.86	1.90	2.05
	B30R090	0.68	0.88	1.92	1.67
	B30R100	0.71	0.94	1.91	1.93

2.Comparison Table of Standards and Grades for Grain-Oriented Silicon Steel

列	公称厚度 (mm)	宝钢 Baosteel	武钢 WISCO	新日铁 NSC	JFE	Congent	蒂森克虏伯 TKS	浦项 Posco	新利佩茨克 NI & SCo	阿姆可 AK
Normal	0.23	B23G110	23Q105
			23Q110	23Z110			C110-23		NV23S -
			23Q115
		B23G120				M120 -	C120-23		NV23S -	M-3
						M127 -	C127-23		NV23S -
	0.27							27PG110	NV27S -
		B27G120	27Q120	27Z120	27JG120		C120-27	27PG120	NV27S -	M-4
		B27G130	27Q130	27Z130	27JG130	M130 -	C130-27	27PG130	NV27S -	M-4
			27Q140			M140 -	C140-27		NV27S-14
	0.3							30PG110
		B30G120	30Q220	30Z120	30JG120			30PG120	NV30S -
		B30G130	30Q180	30Z130	30JG130		C130-30	30PG130	NV30S -
		B30G140	30Q160	30Z140	30JG140	M140 -	C140-30	30PG140	NV30S -	M-5
			30Q150			M150 -	C150-30			M-5
			30Q140
			30Q130
			30Q120
	0.35	B35G135	35Q135	35Z135	35JG135				NV35S -
		B35G145	35Q145	35Z145	35JG145	M150 -	C150-35	35PG145	NV35S -	M-6
		B35G155	35Q155	35Z155	35JG155	M165 -	C165-35	35PG155		M-6
High magnetic induction type	0.23	B23P090	23QG090	23ZH090	23JGS090 23JGH090	M90 -23P5	H090-23	23PH090
		B23P095	23QG095	23ZH095	23JGS095 23JGH095		H095-23	23PH095
		B23P100	23QG100	23ZH100	23JGH100	M100 -	H100-23	23PH100		H-0
				23ZH110
	0.27						H090-27
		B27P095	27QG095	27ZH095			H095-27	27PH095
		B27P100	27QG100	27ZH100	27JGH100	M103 -	H103-27	27PH110	NV27P-
		B27P110	27QG110	27ZH110	27JGH110					H-1
	0.3	B30P100	30QG100	30ZH100	30JGH100			30PH100
		B30P105	30QG105	30ZH105	30JGH105	M105 -	H105-30	30PH105	NV30P-
		B30P110	30QG110	30ZH110	30JGH110	M111 -	H111-30
		B30P120	30QG120	30ZH120	30JGH120	M117 -
	0.35	B35P115		35ZH115	35JGS115 35JGH115			35PH115
		B35P125		35ZH125	35JGS125 35JGH125			35PH125
		B35P135		35ZH135	35JGH135			35PH135
High magnetic induction type with domain refinement	0.23	B23R080		23ZDKH80 23ZDMH8	23JGSD80			23PHD080
		B23R085		23ZD0KH85 23ZDMH8	23JGSD85		H085-23	23PHD085
		B23R090		23ZD5KH90 23ZDMH9	23JGSD90		H090-23			H-0DR
	0.27	B27R090		27ZD0KH90 27ZDMH9	27JGSD90		H090-27	27PHD090
		B27R095		27ZD0KH95 27ZDMH9	27JGSD95			27PHD095		H-1DR

3. Core Advantages and Technical Characteristics of Grain-Oriented Silicon Steel

The key advantage of grain-oriented silicon steel is its excellent magnetic properties along the rolling direction. This comes from precise Goss texture ({110}<001>) control.

Low Core Loss – High-purity melting, proper inhibitors, and secondary recrystallization reduce eddy current and hysteresis loss. Core loss is much lower than non-oriented steel. This minimizes heat and energy loss in transformers.

High Magnetic Induction – Magnetic polarization exceeds 1.88 T (at 800 A/m). Higher flux density reduces core size, weight, and cost.

Low Magnetostriction – Suppressed magnetostriction lowers vibration and noise. Meets quiet urban power supply requirements.

Excellent Lamination Factor – Tight tolerance (±0.005 mm) and smooth surfaces give a stacking factor >0.96. This improves the magnetic circuit.

Surface Insulation Coating – Phosphate or chromate coatings (T1–T3) provide insulation, heat resistance, adhesion, and punchability. Some products use laser scribing to further reduce core loss.

In summary, grain-oriented silicon steel is irreplaceable for power and distribution transformer cores. This is due to texture control, thin rolling, and advanced coatings.

4. Application Fields of Grain-Oriented Silicon Steel

Thanks to low core loss and high magnetic induction, grain-oriented silicon steel is mainly used for transformer cores. It is also expanding into other high-efficiency electromagnetic devices.

Main applications include:

Power Transformers – Used in large transformers (above 10 MVA) for power plants, substations, and high-voltage grids. Low core loss reduces no‑load loss and improves efficiency.
Distribution Transformers – Used in 10 kV / 0.4 kV networks. Includes pole‑mounted, pad‑mounted, and dry‑type transformers. This is the largest market. Conventional thicknesses (0.23–0.35 mm) are common. Some high‑efficiency units now use 0.20 mm and thinner.
Medium‑to‑High Frequency Transformers – Ultra‑thin gauges (0.15, 0.10, 0.08, 0.05 mm) are used for 200 Hz – 10 kHz. Examples: rail traction converters, PV inverters, wind generators, induction heating, and military power supplies.
Pulse Transformers & Magnetic Amplifiers – Used in radar, laser power supplies, and particle accelerators. Benefit from fast magnetization and low loss of ultra‑thin steel.
Reactors & Chokes – Used for short‑circuit current limiting, filtering, and reactive power compensation. This steel improves linearity and reduces losses.
Current & Voltage Transformers – Require high permeability and low angle error. High‑induction steel improves measurement accuracy.

Grain-oriented silicon steel is also finding use in high‑efficiency motors, magnetic shielding, and renewable energy equipment. Demand will grow with smart grids, EV charging, and distributed energy.

5. Production Process and Quality Control of Oriented Silicon Steel at Zhongxin Special Steel

Zhongxin Special Steel uses a full precision process. Impurities (C, S, N) are strictly controlled. Inhibitors (AlN, MnS) help form Goss texture.

Process: hot rolling, normalizing, cold rolling (±0.005 mm), decarburizing annealing, MgO coating, then high‑temperature batch annealing (>1200°C in pure hydrogen) to create a sharp Goss texture. An inorganic coating (T2/T3) is applied. Laser scribing is optional for lower core loss.

Thickness: conventional 0.20–0.35 mm, ultra‑thin 0.15/0.10/0.08/0.05 mm. Slitting: 20–600 mm (conventional) or 10–300 mm (ultra‑thin). Also cut‑to‑length sheets.

Quality: tight control of purity and inclusions. Each coil tested for core loss (e.g., 0.27 mm grade: P₁.₇/₅₀ ≤ 1.10 W/kg) and J₈₀₀ per IEC/GB. EBSD/XRD checks texture. Thickness, flatness, coating adhesion and resistance are monitored. Lamination factor >0.96. MES system ensures full traceability and consistent performance.

6. Packaging and Transportation

Grain-oriented silicon steel coils rust easily from moisture. Professional packaging is very important for B2B customers. Zhongxin Special Steel uses the following solutions:

Moisture-Proof Packaging – Vertical packaging is used. Two options are available: Eye-to-Sky and Eye-to-Wall. Eye-to-Sky means the coil axis is vertical. The eye faces upward. The inner layer uses plastic film and VCI rust-proof paper. The outer layer has steel strapping, corner protectors, and steel sheathing. This provides excellent moisture protection and allows stacking. Eye-to-Wall means the coil axis is horizontal. The eye faces sideways. End faces are sealed more tightly. This makes lifting and unpacking easier. Both methods stop moisture during storage and transport.

Wooden / Steel Pallets – Coils are placed on wooden pallets or steel pallets. Wooden pallets meet ISPM 15 standards. They use heat‑treated or fumigated solid wood with IPPC marks. Wooden pallets are for one‑way export and cross‑border shipping. Steel pallets are reusable. They are ideal for closed‑loop supply chains and multiple trips. They offer stable support and need no fumigation.

Container Lashing – After loading, wooden wedges block both sides of the coil base. This prevents rolling. Steel wire ropes or strapping belts go through the coil eye. They are tightened to the container’s side lashing rings. Air bags fill the gaps. This stops the coil from shifting or bumping during sea transport and rough handling. Each shipment includes lashing photos and records for customer inspection.

7.FAQ

1.What is the difference between CRGO and CRNGO silicon steel?

CRGO (Cold Rolled Grain Oriented) silicon steel has a uniform grain orientation, offering high magnetic permeability and low core loss in a specific direction, making it ideal for transformers. CRNGO (Cold Rolled Non-Oriented) steel has a random grain structure, which uniformizes magnetic properties in all directions, suitable for rotating machinery like electric motors and generators.

2.What standards and grades of grain oriented silicon steel do you supply?

We supply high-quality CRGO steel compliant with major international standards including AISI/ASTM, JIS, EN, and GB. Available regular and Hi-B grades include 23ZH090, 27ZH100, 30G130, M130-30S, and custom ultra-thin specifications (0.18mm, 0.20mm) tailored for high-efficiency transformer cores.

3.Can you provide slitting and cutting services for CRGO steel coils?

Yes, we provide professional value-added processing services. We can slit wide CRGO coils into precise narrow strips (minimum width based on client requirements) or provide cut-to-length lamination sheets to match your specific transformer core design.

4.How do you ensure the quality and prevent rust during shipping?

Every shipment is strictly tested via Epstein Frame before dispatch and comes with a Mill Test Certificate (MTC) compliant with EN 10204 3.1. For logistics, we utilize seaworthy ‘Eye-to-Sky’ or ‘Eye-to-Wall’ packaging with anti-rust paper, plastic film, steel strapping, and robust wood/iron pallets to prevent moisture and damage.