Hot Leveling Annealing For Grain-Oriented Silicon Steel
Oct 20, 2025
Kite yon mesaj
Grain-Oriented Silicon Steel
After high-temperature annealing, grain-oriented silicon steel must undergo hot leveling and insulating coating application.
During high-temperature annealing of grain-oriented silicon steel coils, the steel strip becomes uneven due to thermal stress. Therefore, stretch leveling annealing is necessary to flatten the steel strip. Additionally, excess coating residue from the previous process must be removed before applying the insulating film.
First, the residual special coating (MgO) and other contaminants on the steel strip surface are removed through water scrubbing and light pickling with dilute sulfuric acid. After that, the strip is thoroughly cleaned and dried.
The mass fraction of sulfuric acid ranges from 4% to 8%.
The pickling temperature is controlled between 70℃ and 90℃.
Apply the insulating coating and dry the strip at a temperature below 500℃.
Conduct coating sintering in a continuous furnace with a nitrogen atmosphere, and apply appropriate tension to stretch and level the steel strip.
The annealing temperature is controlled between 830℃ and 900℃, varying according to the coating type, steel sheet thickness, and unit speed.
During stretch hot leveling, the minimum tension that keeps the steel strip flat without reducing its magnetic properties should be selected, generally controlled between 3 N/mm² and 6 N/mm².
During cooling, the steel strip must be cooled uniformly along its width to ensure good flatness.
Raw Material: Our premium CRGO silicon steel is sourced exclusively from renowned manufacturers, Baosteel and WISCO, ensuring top-tier quality for your transformer core laminations.
GRADE we supply:B30P120, B30P105, B30R100, 27QG120, 27QG100, 23Q110, 23QG100, 23QG095, 23RK090, 23RK085, 23QG085, 23RK085, 23QG085, 23RK080, 23RK075, B23R070, 20QG085, 20RK080, 20RK075, B20R070, B20R065,M0H,M1H,M2,M3,M4,M5.
23HP75d, 23HP80d, 23HP85d, 23HP90d, 23HP95d, 23HP100, 23HP100d, 27HP100, 27HP110, 27CG110, 27CG120, 30CG120, 30CG130
| Max Core Loss@P1.7T/50Hz | Min Induction@B800 | ||||
| 23Q110 | 35-1200mm | 1.10w/kg | 97.2 | 1.82T | |
| 23Q120 | 1.20w/kg | 97.2 | 1.82T | ||
| 27Q120 | 1.20w/kg | 97.5 | 1.82T | ||
| 30G120 | 1.20w/kg | 98 | 1.82T | ||
| B20P085 | 35-1200mm | 0.85w/kg | 97 | 1.86T | |
| B23P085 | 0.85w/kg | 97.2 | 1.88T | ||
| B23P090 | 0.90w/kg | 97.2 | 1.88T | ||
| B23P095 | 0.95w/kg | 97.2 | 1.88T | ||
| B23P100 | 1.00w/kg | 97.2 | 1.88T | ||
| B27P095 | 0.95w/kg | 97.5 | 1.89T | ||
| 27QG100 | 1.00w/kg | 97.5 | 1.89T | ||
| B30P105 | 1.05w/kg | 98 | 1.89T | ||
| B20R070 | 35-1200mm | 0.70w/kg | 97 | 1.86T | |
| B23R085 | 0.85w/kg | 97.2 | 1.88T | ||
| B27RK085 | 0.85w/kg | 97.5 | 1.89T |
We meticulously calculate and regularly update quotations based on your comprehensive drawings, ensuring precision and cost-effectiveness in every transaction.
Upon receiving your confirmation, we seamlessly transition into production, adhering stringently to the meticulously detailed drawings you provide to ensure flawless execution.
Gnee provides premium iron cores to the world. Our cores can be selected in a wide range of materials, shapes, applications, manufacturing techniques, etc., to meet customers' diverse demands. Explore our wide product range now~
1. Raw Material Sourcing
2. Slitting
3. Punching
4. Laminating
5. Core Forming
6. testing
Founded in 2008 and located in Anyang in China, Gnee Electric is a high-tech enterprise specializing in researching and manufacturing iron core products.
The company currently occupies over 20,000 square meters and employs more than 200 people, including over 80 professionals. After more than 18 years of development, we have built our own magnetic material production base and independently develope, produce, and sell various kinds of iron cores. The common types include silicon steel cores, motor cores, transformer cores, toroidal iron cores, special-shaped cores, custom cores, and others. Our cores are widely applied in different sectors including transformers, motors, mutual inductors, voltage stabilizers, welding machines, magnetic amplifiers, and instrumentation, providing diverse core solutions to global customers.
30+
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GNEE EC was founded in 2008, which is a National High-tech Enterprise & Famous Brand Enterprise in China, developing into a professional manufacturer and supplier of high-quality iron cores.
18+
Over 18 years of success in the iron core industry;
National High-tech Enterprise & Famous Brand Enterprises in China;
200+
Over 200 employees;
The R&D team has more than 80 experienced engineers and the production team has more than 100 skilled staffs;
35+
Annual turnover up to 35 million dollor per year;
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Over 1000 customers in domestic and overseas markets;
core Products are exported to more than 70 countries in the world;
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