Electrical steel is one of the most critical materials used in modern electrical infrastructure. Among different electrical steel grades, 23Q90 grain oriented silicon steel is one of the most commonly used materials for transformer cores.
For engineers, transformer manufacturers, and procurement teams, understanding the meaning behind electrical steel grade designations is essential when selecting materials for transformer production.
Grades such as 23Q90, 23Q95, and 27Q120 describe important technical characteristics of the material, including thickness, magnetic properties, and energy loss performance.
These parameters directly influence the efficiency and reliability of transformers operating within electrical power systems.
Quick Answer
The designation 23Q90 refers to a grade of grain oriented electrical steel commonly used in transformer cores.
In this designation:
23 represents the nominal thickness of the steel sheet, approximately 0.23 mm
Q indicates grain oriented electrical steel
90 represents the maximum core loss value of about 0.90 W/kg under standard testing conditions
This grade provides a balanced combination of efficiency and cost, making it widely used in distribution transformers and medium-power transformer applications.
Electrical Steel in Transformer Design
Transformers are essential components in electrical transmission and distribution networks. They allow electricity to be transferred between circuits at different voltage levels.
The transformer core serves as the magnetic pathway that allows magnetic flux to circulate between the windings.
To achieve efficient energy transfer, the core material must exhibit excellent magnetic properties.
Key characteristics required for transformer core materials include:
high magnetic permeability
low hysteresis loss
low eddy current loss
stable magnetic performance
Electrical steel is specifically developed to meet these requirements.
Among electrical steel types, grain oriented silicon steel (CRGO) has become the dominant material used in transformer cores.
Grain Oriented Silicon Steel Explained
Grain oriented electrical steel is produced using specialized metallurgical processes that align the crystal grains of the steel in a specific direction.
During manufacturing, rolling and heat treatment processes control the orientation of the grains so that the magnetic easy axis aligns with the rolling direction.
This grain alignment allows magnetic flux to pass through the steel with less resistance.
As a result, grain oriented silicon steel provides several advantages compared with non-oriented electrical steel:
higher magnetic permeability
lower core loss
improved transformer efficiency
reduced heat generation
Because transformer cores operate under predictable magnetic flux directions, grain oriented steel significantly improves efficiency compared with conventional steels.
Interpreting the 23Q90 Grade Designation
Electrical steel grades typically include numbers and letters that describe the material's properties.
The grade 23Q90 can be interpreted as follows.
Thickness
The number 23 refers to the nominal thickness of the steel sheet.
Electrical steel thickness is usually measured in millimeters. In this case, the thickness corresponds to 0.23 mm.
Thickness is an important factor in determining electrical steel performance because it influences eddy current losses.
Thinner sheets reduce eddy current losses and improve efficiency.
Typical CRGO steel thickness ranges include:
0.18 mm
0.20 mm
0.23 mm
0.27 mm
0.30 mm
Among these, 0.23 mm thickness is widely used in transformer core laminations.
Grain Orientation Identifier
The letter Q indicates that the steel is grain oriented electrical steel.
Grain orientation allows the steel to exhibit improved magnetic permeability in the rolling direction.
This property enables transformer cores to guide magnetic flux more efficiently.
Without grain orientation, electrical steel would experience higher losses during magnetization cycles.
Core Loss Performance
The number 90 represents the maximum core loss value under standardized testing conditions.
Core loss is measured in watts per kilogram (W/kg).
For the 23Q90 grade, the core loss value is approximately 0.90 W/kg under the testing condition known as P1.7/50.
This testing condition refers to:
magnetic flux density of 1.7 Tesla
frequency of 50 Hz
Lower core loss values indicate better magnetic performance and improved transformer efficiency.
Magnetic Performance of 23Q90 Steel
Several magnetic parameters are used to evaluate the performance of CRGO steel.
Core Loss
Core loss represents the energy dissipated during magnetization cycles.
It includes both hysteresis loss and eddy current loss.
Reducing core loss improves transformer efficiency and reduces heat generation.
Magnetic Flux Density
Magnetic flux density indicates the material's ability to carry magnetic flux.
Typical CRGO steels have magnetic flux density values ranging from 1.85 Tesla to 1.89 Tesla.
Higher flux density enables transformer designers to achieve compact core designs while maintaining high efficiency.
Comparison of Common CRGO Grades
Transformer manufacturers use a range of CRGO grades depending on performance requirements.
|
Grade
|
Thickness
|
Core Loss
|
Magnetic Flux Density
|
| 23Q85 |
0.23 mm
|
0.80 – 0.85 W/kg
|
1.85 – 1.89 T
|
| 23Q90 |
0.23 mm
|
0.85 – 0.90 W/kg
|
1.85 – 1.89 T
|
| 23Q95 |
0.23 mm
|
0.89 – 0.91 W/kg
|
1.85 – 1.89 T
|
| 23Q100 |
0.23 mm
|
0.90 – 0.97 W/kg
|
1.85 – 1.89 T
|
| 27Q120 |
0.27 mm
|
1.05 – 1.15 W/kg
|
1.85 – 1.89 T
|
Lower core loss grades are generally used in high-efficiency transformer designs.
However, cost and project specifications also influence material selection.
Manufacturing Process of CRGO Electrical Steel
The production of grain oriented electrical steel involves multiple complex metallurgical processes.
Typical production stages include:
steelmaking and silicon alloying
hot rolling
pickling
cold rolling
decarburization annealing
secondary recrystallization
insulation coating
The secondary recrystallization process is particularly important because it creates the grain structure responsible for the steel's magnetic properties.
Only a limited number of steel producers worldwide possess the technology required to manufacture high-quality CRGO steel.
Transformer Core Lamination Production
Before being assembled into transformer cores, electrical steel coils are processed into laminations.
Typical processing operations include:
coil slitting
strip cutting
step-lap punching
core stacking
Step-lap core designs are commonly used in modern transformers because they reduce magnetic flux leakage and improve efficiency.
Precision during lamination production is critical for maintaining consistent transformer performance.
Global Supply and Material Processing
CRGO electrical steel is typically supplied in coil form and then processed into strips or laminations.
In the transformer industry, suppliers often provide additional processing services including:
coil slitting
custom width cutting
small-batch supply
trial material supply
Flexible supply is important for transformer manufacturers that must support multiple projects with varying design requirements.
Material suppliers such as MOOPEC support transformer manufacturers by offering flexible supply solutions including customized specifications and small-batch electrical steel supply.
Industry Demand for Transformer Steel
Global demand for electrical steel continues to increase as electricity consumption grows worldwide.
Key drivers include:
renewable energy expansion
electric vehicle infrastructure
power grid modernization
data center electricity demand
Modern data centers and digital infrastructure require significant electrical capacity, increasing demand for transformers and electrical steel materials.
Grain oriented silicon steel remains a fundamental material supporting modern power systems.
Key Takeaways
23Q90 is a widely used grain oriented silicon steel grade for transformer cores.
The number 23 represents the steel thickness of approximately 0.23 mm.
The letter Q indicates grain oriented electrical steel.
The number 90 refers to the maximum core loss value of approximately 0.90 W/kg.
This grade provides a practical balance between efficiency and cost in transformer manufacturing.
FAQ
What does 23Q90 mean in electrical steel?
23Q90 refers to grain oriented silicon steel with a thickness of 0.23 mm and a maximum core loss value of approximately 0.90 W/kg.
Where is 23Q90 electrical steel used?
It is commonly used in distribution transformers and medium-power transformer cores.
What is the difference between 23Q85 and 23Q90?
23Q85 has slightly lower core loss and therefore slightly better magnetic efficiency.
Why is thickness important in electrical steel?
Thinner electrical steel reduces eddy current losses and improves transformer efficiency.