What are the Chemical Composition and Properties of 0.23mm Cold-Rolled Silicon Steel Sheets?
May 25, 2026
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Cold-rolled silicon steel sheets are a special type of silicon alloy steel produced through a cold rolling process, primarily used for making cores of motors, transformers, and generators. They exhibit excellent magnetic and electrical properties, making them crucial materials in power equipment.
In this comprehensive guide, we focus specifically on the chemical composition and properties of cold-rolled silicon steel sheets with a thickness of 0.23mm-one of the most widely specified gauges for high-performance transformer cores and rotating machinery. You will find detailed parameters on silicon content, magnetic core loss values, mechanical properties, coating specifications, and practical guidance on how to select the right grade for your specific application.
Whether you are a transformer manufacturer looking to reduce no-load losses or a motor producer aiming for higher efficiency ratings, this resource will help you make an informed procurement decision.
What Are 0.23mm Cold-Rolled Silicon Steel Sheets?
Cold-rolled silicon steel, also known as electrical steel or lamination steel, is a low-carbon iron-silicon alloy specifically engineered for electromagnetic applications. The cold rolling process involves reducing the thickness of hot-rolled steel strip through controlled deformation at room temperature, followed by precise annealing treatments that develop the desired grain structure and magnetic properties.
0.23mm cold-rolled silicon steel sheets represent a premium thin-gauge category within this family, offering the ideal balance between low core loss and mechanical workability. This ultra-thin thickness significantly reduces eddy current losses-a critical advantage in high-frequency transformers and compact motor cores where every fraction of a millimeter matters.
The primary reason manufacturers specify 0.23mm sheets is simple: thinner laminations mean lower eddy current losses. When a magnetic field alternates inside a transformer core, eddy currents circulate within each sheet. The thinner the sheet, the shorter the path for these currents, and the less energy is wasted as heat. For 0.23mm sheets, eddy current losses are dramatically reduced compared to 0.35mm or 0.50mm alternatives, making them the go-to choice for high-efficiency distribution transformers and traction motors.
Complete Chemical Composition of 0.23mm silicon steel
Below is the typical chemical composition for premium-grade 0.23mm cold-rolled grain-oriented silicon steel sheets, based on industry standards and mill specifications:
| Element | Typical Range (wt%) |
|---|---|
| Silicon (Si) | 3.0 – 3.4% |
| Carbon (C) | ≤ 0.02 – 0.03% |
| Manganese (Mn) | 0.08 – 0.20% |
| Phosphorus (P) | ≤ 0.015 – 0.02% |
| Sulfur (S) | ≤ 0.003 – 0.005% |
| Aluminum (Al) | ≤ 0.005% |
| Nitrogen (N) | ≤ 0.002 – 0.003% |
| Iron (Fe) | Balance (~96–97%) |
Iron Loss
Core loss, measured in watts per kilogram (W/kg), represents the energy dissipated as heat when the steel is subjected to an alternating magnetic field. It consists of two components: hysteresis loss (caused by the energy required to realign magnetic domains) and eddy current loss (caused by circulating currents within the sheet).
For 0.23mm grades, core loss values are specified at 1.7 Tesla and 50 Hz (standard power frequency). Typical values include:
| Grade | Nominal Core Loss P₁.₇/₅₀ (W/kg) | Application Level |
|---|---|---|
| B23R085 (Hi-B) | ≤ 0.85 | Ultra-high efficiency |
| 23Q110 (Conventional) | ≤ 1.10 | High-efficiency distribution transformers |
| H23QK100 (Domain-refined) | ≤ 1.00 | Premium domestic grade |
| B23G110 | ≤ 1.10 | Standard industrial grade |
The 0.85 W/kg core loss achieved by Hi-B (high permeability) grades like B23R085 represents the current industry benchmark for ultra-efficient transformers. Each 0.1 W/kg reduction in guaranteed core loss delivers meaningful annual energy savings, especially in continuous-duty applications such as utility distribution transformers
Surface Insulation Coating
All 0.23mm cold-rolled silicon steel sheets are supplied with an inorganic insulation coating applied during final processing. This coating serves two critical purposes:
- Interlaminar insulation – Prevents electrical contact between stacked laminations, eliminating eddy current flow from sheet to sheet
- Corrosion protection – Protects the steel surface during storage, transport, and handling
The most common coating types for 0.23mm grades are C5 (inorganic phosphate-based, chromate-free) and C6 (high-adhesion grade). These coatings deliver inter-laminar resistance of 800–1000 V per layer and excellent heat resistance during core annealing operations
Applications of 0.23mm Cold-Rolled Silicon Steel Sheets
- Power & distribution transformers (15 kV – 36 kV) – The high magnetic permeability and low core loss significantly reduce no-load losses, helping utilities meet stringent efficiency regulations (DOE/CEE Tier 2 compliant).
- High-frequency transformers (400 Hz and above) – The thin 0.23 mm gauge minimizes eddy current losses at elevated frequencies, making these sheets ideal for pulse transformers, magnetic amplifiers, and converters in aerospace and military applications.
- EV traction motors – Advanced electric vehicle motors require high magnetic flux density and minimized core loss to maximize range and power density.
- Large generators – Stator cores in high-efficiency generators benefit from the directional magnetic properties and low hysteresis loss of grain-oriented silicon steel.
Ready to optimize your electrical equipment with premium 0.23mm cold-rolled silicon steel sheets?
Contact GNEE Steel today with your thickness, width, core loss requirement, and target quantity. Our team will provide a detailed quotation, material certificate, and lead time within 24 hours.
What are cold rolled steel sheets used for?
Cold rolled steel sheets offer a variety of outstanding properties, including easy formability and a smooth, clean surface, and are used in automobiles, appliances, furniture, and many other everyday items.
What is the thickness of silicon steel?
Silicon Steel - 0.35mm To 0.65mm Thickness, 1000mm Or 1200mm Width | High Dimension Accuracy, Low Core Loss, Excellent Sound Insulation Properties.
What is the silicon content of steel?
Grain orientation
Grain-oriented electrical steel usually has a silicon level of 3%
What are the different grades of silicon steel?
There are several grades included in the AISI specification, such as M-47, M-45, M-36, M-27, M-22, M-19 and M-15, all of which are nonoriented silicon-steels.