GB/T 2521.2: Evolution and historical versions
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Cold-rolled electrical steel delivered in the fully-processed state - Part 2: Grain-oriented steel strip(sheet)
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GB/T 2521.2-2025
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| GB/T 2521.2-2016 | English | 150 |
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Cold-rolled electrical steel delivered in the fully-processed state -- Part 2: Grain-oriented steel strip (sheet)
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GB/T 2521.2-2016
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Basic data | Standard ID | GB/T 2521.2-2025 (GB/T2521.2-2025) | | Description (Translated English) | Cold-rolled electrical steel delivered in the fully-processed state - Part 2: Grain-oriented steel strip(sheet) | | Sector / Industry | National Standard (Recommended) | | Date of Implementation | 2026-03-01 | | Older Standard (superseded by this standard) | GB/T 2521.2-2016 | GB/T 2521.2-2016: Cold-rolled electrical steel delivered in the fully-processed state -- Part 2: Grain-oriented steel strip (sheet)
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Cold-rolled electrical steel delivered in the fully-processed state - Part 2. Grain-oriented steel strip (sheet)
ICS 77.140.40
H53
National Standards of People's Republic of China
Partially replace GB/T 2521-2008
Full process cold rolled electrical steel
Part 2. Grain oriented steel strip (sheet)
Part 2. Grain-orientedsteelstrip(sheet)
(IEC 60404-8-7.2008, Magneticmaterials-Part 8-7. Specificationsfor
Andsheetdeliveredinthefuly-processedstate, MOD)
2016-06-14 released.2017-05-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Content
Foreword I
1 Scope 1
2 Normative references 1
3 Terms and Definitions 1
4 Category 2
5 symbols and grades 2
6 General requirements 3
7 Technical requirements 4
8 Inspection and test 7
9 Judgment and re-examination rules 9
10 Packaging, Marking and Quality Certificate 10
11 Ordering Content 10
Appendix A (Normative Appendix) Repeated Bending Test Method 11
Appendix B (Normative) Test Method for Coating Insulation Resistance 13
Appendix C (informative) Characteristics and main uses of each grade 14
Appendix D (informative appendix) This part and IEC 60404-8-7.2008 brand comparison table 16
Appendix E (informative) This section is numbered in accordance with the IEC 60404-8-7.2008 chapter number.
Appendix F (informative) Technical differences and causes of this part and IEC 60404-8-7.2008 19
Foreword
GB/T 2521 "Full Process Cold Rolled Electrical Steel" is divided into the following two parts.
--- Part 1. Grain non-oriented steel strip (sheet);
--- Part 2. Grain oriented steel strip (sheet).
This part is the second part of GB/T 2521.
This part is drafted in accordance with the rules given in GB/T 1.1-2009.
This part replaces "cold rolled oriented electrical steel strip (sheet)" in GB/T 2521-2008 "Cold-rolled oriented and non-oriented electrical steel strip (sheet)"
In part, compared with GB/T 2521-2008, the main technical changes are as follows.
--- The standard name is adjusted to "Full Process Cold Rolled Electrical Steel Part 2. Grain Oriented Steel Strip (Sheet)";
--- Removed all the contents of cold rolled non-oriented electrical steel;
--- Increased the range of the inner diameter of the coil;
--- Increased magnetic domain refinement level 11 grades; canceled 23Q130, 27Q110, 27Q140, 30Q140, 30Q150, 35Q135
A total of 6 brands;
---The steel grades are divided into three categories. ordinary grade, high magnetic polarization level, and magnetic domain refinement level;
--- Increased the magnetic polarization of each grade;
---"Magnetic characteristics" was changed to "magnetic properties", "process characteristics" was changed to "technical characteristics";
---Adjusted steel strip (sheet) thickness tolerance, longitudinal thickness deviation and lateral thickness deviation;
--- Increased steel strip (sheet) file bending requirements;
--- Increase the requirements and test methods for the deviation of the shear edge caused by internal stress;
--- Added Appendix A (normative appendix) repeated bending test method;
--- Added Appendix B (normative appendix) test method for coating insulation resistance;
--- Added the characteristics and main uses of the various grades in Appendix C (informative);
--- Removed Chapter 10 "Objection."
This section uses the redrafting method to modify the use of IEC 60404-8-7.2008 "Magnetic Materials Part 8-7. Full Process Cold Rolling
Specification for the delivery of electrical steel strips (sheets).
This section has more structural adjustments than IEC 60404-8-7.2008. This section is listed in Appendix E.
A list of chapter numbers for IEC 60404-8-7.2008.
There are technical differences between this part and IEC 60404-8-7.2008. The terms involved in these differences have been passed on the outer side of the page.
The vertical single line (|) of the blank position is marked, and a list of the corresponding technical differences and their causes is given in Appendix F. Appendix D gives
Correspondence between this part and the IEC 60404-8-7.2008 grade.
This part was proposed by the China Iron and Steel Association.
This part is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC183).
This section drafted by. Wuhan Iron and Steel (Group) Company, Metallurgical Industry Information Standards Institute, Xinyu Iron and Steel Co., Ltd., Shougang
the company.
The main drafters of this section. Liu Concentration, Hu Shoutian, Zhang Weixu, Zhao Heming, Si Liangying, Mao Yuhui, Yan Yan, Yu Xiaoqin, Qiang, Chen Zhuo,
Chen Xiaohong, Tian Wenzhou, Wang Ruoping.
The previous versions of the standards replaced by this section are.
---GB/T 2521-1981, GB/T 2521-1988, GB/T 2521-1996, GB/T 2521-2008.
Full process cold rolled electrical steel
Part 2. Grain oriented steel strip (sheet)
1 Scope
This part of GB/T 2521 specifies grain-oriented electricians with nominal thicknesses of 0.23mm, 0.27mm, 0.30mm, and 0.35mm.
Terms and definitions, classifications, symbols and grades, general requirements, technical requirements, inspection and testing, determination and re-inspection rules, packaging, marking
Aspirations for quality certificates and ordering contents.
This section applies to the grain-oriented electrical steel strip (sheet) supplied in the whole process cold rolling state used in the magnetic circuit structure [hereinafter referred to as steel strip
(sheet)].
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
General provisions of GB/T 247 steel and steel strip packaging, marking and quality certificates
GB/T 2522-2007 Electrical steel sheet (with) surface insulation resistance, coating adhesion test method (IEC 60404-11..1999,
MOD)
GB/T 2900.60 Electrotechnical terminology electromagnetics [GB/T 2900.60-2002, eqvIEC 60050 (121)..1998]
GB/T 3655 Method for measuring the magnetic properties of electrical steel sheets (belts) with Epstein squares (GB/T 3655-2008, IEC 60404-2.
1996, IDT)
GB/T 9637 Electrotechnical terminology magnetic materials and components [GB/T 9637-2001, eqvIEC 60050 (221)..1990]
GB/T 13789 Method for measuring the magnetic properties of electrical steel sheets (belts) with a single-chip tester (GB/T 13789-2008, IEC 60404-3.
2002, IDT)
General technical requirements for the delivery of GB/T 17505 steel and steel products (GB/T 17505-2016, ISO 404.2013, MOD)
GB/T 18253 Types of inspection documents for steel and steel products (GB/T 18253-2000, eqvISO 10474.1991)
GB/T 19289 Method for measuring the density, resistivity and stacking factor of electrical steel sheets (belts) (GB/T 19289-2003, IEC 404-
13.1995, MOD)
YB/T 4292 Electrical steel strip (sheet) geometrical characteristics test method (YB/T 4292-2012, IEC 60404-9.1987, MOD)
3 Terms and definitions
The following terms and definitions defined in GB/T 2900.60, GB/T 9637 and YB/T 4292 apply to this document.
3.1
Number of bends numberofbends
The maximum number of repeated bendings before the first occurrence of cracks in the substrate (or the sound of cracking was heard) was visually observed.
Note. The ductility of the material is indicated by the number of bends.
3.2
Nominal thickness tolerance deviation nominalhicknesstolerance
The allowable deviation of the nominal thickness in the same acceptance batch.
3.3
Longitudinal thickness deviation longitudinalthicknesstolerance
Parallel to the thickness deviation of a steel sheet or a length of steel strip in the rolling direction.
3.4
Transverse thickness deviation transversethicknesstolerance
A deviation perpendicular to the thickness in the rolling direction.
4 classification
4.1 The grade of the steel strip (sheet) in this section is based on the maximum specific loss value P1.7/50 according to the magnetic polarization at 1.7T and the frequency at 50Hz.
And steel strip (sheet) nominal thickness (0.23mm, 0.27mm, 0.30mm and 0.35mm) for classification, and according to the maximum ratio total loss value P1.7/50
It is subdivided into three categories. ordinary level, high magnetic polarization level and magnetic domain refinement level.
4.2 This part is divided into two types. trimming and non-cutting according to the delivery conditions of steel strip (sheet).
5 symbols and grades
5.1 The symbols and corresponding descriptions in this section are given in Table 1.
Table 1 Symbols and descriptions
Symbol unit description
PW/kg ratio total loss a
P1.5/50 W/kg The total loss measured by magnetic polarization at 1.5T and frequency at 50Hz
P1.5/60 W/kg The total loss measured by magnetic polarization at 1.5T and frequency at 60Hz
P1.7/50 W/kg The total loss measured by magnetic polarization at 1.7T and frequency at 50Hz
P1.7/60 W/kg The total loss measured by magnetic polarization at 1.7T and frequency at 60Hz
HA·m-1 magnetic field strength
JT magnetic polarization
Magnetic polarization of the J800 T magnetic field strength H at 800 A/m (indicated by the peak)
BT magnetic induction
The magnetic permeability in μ0 H/m vacuum is 4πx10-7
C Ω·mm2/face or Ω·cm2/surface insulation resistance value
RA Ω·mm2/piece or Ω·cm2/interlayer resistance
R Ω in series with each contact, equal to 5Ω
A mm2 or cm2 total area of 10 contacts
UV applied to the contacts and the voltage across the 5Ω resistor
IA A current measured each time (10 values)
a Usually called iron loss.
5.2 Steel grades are composed in the order given below.
100 times the nominal thickness (mm) of the material
Characteristic characters. Q--- The initials of the Chinese pinyin indicating the "take" word of the orientation;
G--- the initials of the Chinese pinyin indicating the "high" character of high magnetic polarization;
H--- The initials of the pinyin of the word "chemical" of "domain refinement".
100 times the maximum specific loss value P1.7/50 (W/kg)
Example.
30Q130 represents a common-grade cold-rolled grain-oriented electrical steel strip (sheet) with a nominal thickness of 0.30 mm and a maximum specific loss of P1.7/50 of 1.30 W/kg;
30QG110 represents a high magnetic polarization grade cold rolled grain oriented electrical steel strip with a nominal thickness of 0.30 mm and a maximum specific loss of P1.7/50 of 1.10 W/kg.
(sheet);
30QH100 represents a magnetic domain refinement grade cold-rolled grain-oriented electrical steel strip with a nominal thickness of 0.30 mm and a maximum specific loss of P1.7/50 of 1.00 W/kg.
(sheet).
6 General requirements
6.1 Production process
The production process and chemical composition of the steel are determined by the manufacturer.
6.2 Form of supply
The steel strip is supplied in rolls and the steel sheets are supplied in boxes. The specific requirements are as follows.
a) The weight of the coil and box should meet the ordering requirements, and the weight of the steel coil is generally 2t~5t;
b) The inner diameter of the coil should be 500mm~520mm, and the recommended inner diameter is 508mm;
c) the side of the steel sheet stack should be flat, and the near vision is perpendicular to the upper surface;
d) The coils shall be tightly wound from steel strips of the same width so that they do not collapse under their own weight and the sides of the coils should be as straight as possible;
e) The steel strip may be joined or welded due to the removal of defects. The joints or welds shall be marked. The front and rear of the joint or weld shall be
The same grade, and no more than 2, the length of the steel strip between the welds shall not be less than.200m;
f) The weld should be flat and does not affect the subsequent processing of the material.
6.3 Delivery conditions
The steel strip (sheet) is usually delivered in a trimmed state. When the user has special requirements, the agreement can be delivered without the trimming status. Steel strip before delivery
(Slice) Both sides should be coated with an insulating coating. The type of insulating coating is determined by negotiation between the supplier and the buyer.
6.4 Surface conditions
6.4.1 The surface of the steel strip (sheet) should be smooth and free of rust. Allowed within the thickness tolerance and does not interfere with the normal use of the material, allowing
There are defects in the dispersion distribution such as scratches, bubbles, cracks, and the like.
6.4.2 The insulating coating on the surface of the steel strip (sheet) should be well adhered, and the color of the coating should be uniform to ensure the cutting operation and the manufacturer's recommendation.
The metal is not peeled off during annealing under stress relief annealing conditions.
Note. If the product is specified in the protocol to be submerged in liquid, ensure compatibility between the liquid and the coating.
6.5 Shear adaptability
The strip should be easy to shear and should be able to cut the strip into the usual shape at any location.
7 Technical requirements
7.1 Magnetic properties
7.1.1 The magnetic properties of steel strips (sheets) provided under 6.3 shall be in accordance with Table 2, Table 3 and Table 4. Aging samples should also meet these
characteristic. For coated products, the quality of the insulating coating should be taken into account.
7.1.2 The magnetic properties of the steel strip (sheet) shall be tested in accordance with GB/T 3655, but the steel strip produced in the non-heat-resistant magnetic domain refinement (such as laser scoring method) in Table 4
The magnetic properties of (sheet) shall be tested in accordance with GB/T 13789. After consultation between the supplier and the buyer, the magnetic properties of the steel strip (sheet) can also be tested according to GB/T 13789.
The test values shall comply with the requirements of Table 2, Table 3 and Table 4.
Note 1. For many years, it has been customary to use magnetic induction. In fact, the Epstein square and the monolithic tester measure the magnetic polarization.
Relationship between magnetic induction and magnetic polarization. J=B-μ0H
Note 2. There will be differences in the results of the same steel strip (sheet) according to GB/T 3655 and GB/T 13789.
Table 2 Magnetic properties and technical characteristics of ordinary grade steel strips (sheets)
Brand nominal thickness/mm
Maximum specific loss P/(W/kg)
P1.5/50a P1.5/60a P1.7/50 P1.7/60b
Minimum magnetic polarization J/T
50Hz or 60Hz
J800
Minimum stacking factor
23Q110
23Q120
0.23
0.73
0.77
0.96
1.01
1.10
1.20
1.45
1.57
1.82
1.82
0.945
27Q120
27Q130
0.27
0.80
0.85
1.07
1.12
1.20
1.30
1.58
1.68
1.82
1.82
0.950
30Q120
30Q130
0.30
0.79
0.85
1.06
1.15
1.20
1.30
1.58
1.71
1.82
1.82
0.955
35Q145
35Q155
0.35
1.03
1.07
1.36
1.41
1.45
1.55
1.91
2.04
1.82
1.82
0.960
a is the reference value.
b According to user requirements, it can be supplied according to P1.7/60.
Table 3 Magnetic properties and technical characteristics of high magnetic polarization grade steel strips (sheets)
Brand nominal thickness/mm
Maximum specific loss P/(W/kg)
P1.7/50 P1.7/60a
Minimum magnetic polarization J/T
50Hz or 60Hz
J800
Minimum stacking factor
23QG085
23QG090
23QG095
23QG100
0.23
0.85
0.90
0.95
1.00
1.12
1.19
1.25
1.32
1.88
1.88
1.88
1.88
0.945
27QG090
27QG095
27QG100
27QG110
0.27
0.90
0.95
1.00
1.10
1.19
1.25
1.32
1.45
1.88
1.88
1.88
1.88
0.950
Table 3 (continued)
Brand nominal thickness/mm
Maximum specific loss P/(W/kg)
P1.7/50 P1.7/60a
Minimum magnetic polarization J/T
50Hz or 60Hz
J800
Minimum stacking factor
30QG105
30QG110
30QG120
0.30
1.05
1.10
1.20
1.38
1.46
1.58
1.88
1.88
1.88
0.955
35QG115
35QG125
35QG135
0.35
1.15
1.25
1.35
1.51
1.64
1.77
1.88
1.88
1.88
0.960
a According to user requirements, it can be supplied according to P1.7/60.
Table 4 Magnetic properties and technical characteristics of magnetic domain refining grade steel strips (sheets)
Brand nominal thickness/mm
Maximum specific loss/(W/kg)
P1.7/50 P1.7/60a
Minimum magnetic polarization/T
50Hz or 60Hz
J800
Minimum stacking factor
23QH080
23QH085
23QH090
23QH100
0.23
0.80
0.85
0.90
1.00
1.06
1.12
1.19
1.32
1.88
1.88
1.88
1.88
0.945
27QH085
27QH090
27QH095
27QH100
0.27
0.85
0.90
0.95
1.00
1.12
1.19
1.25
1.32
1.88
1.88
1.88
1.88
0.950
30QH095
30QH100
30QH110
0.30
0.95
1.00
1.10
1.25
1.32
1.46
1.88
1.88
1.88
0.955
a According to user requirements, it can be supplied according to P1.7/60.
7.2 Geometric characteristics and tolerances
7.2.1 Thickness
7.2.1.1 Nominal thickness
The nominal thickness of the steel strip (sheet) is 0.23 mm, 0.27 mm, 0.30 mm, 0.35 mm.
7.2.1.2 Thickness deviation
The thickness deviation of the steel strip (sheet) shall comply with the requirements of Table 5.
Table 5 Steel strip (sheet) thickness deviation unit is mm
Nominal thickness
Nominal thickness tolerance a longitudinal thickness deviation b lateral thickness deviation c
no greater than
0.23 ±0.020
0.025
0.015
0.27 ±0.025
0.025
0.015
0.30 ±0.025
0.025
0.015
0.35 ±0.025
0.025
0.015
a The thickness increase at the weld shall not exceed 0.050 mm.
b Deviation in thickness of any.2000mm long steel strip or a piece of steel sheet.
c Only for steel strips with a width greater than 150 mm. For narrow strips, a separate agreement is required.
7.2.2 Width
7.2.2.1 The width of the steel strip (sheet) can be selected within the width specified by the manufacturer, generally not exceeding 1050 mm.
7.2.2.2 The allowable deviation of the width of the steel strip (sheet) supplied according to the final use width (ie, the strip) shall comply with the requirements of Table 6;
The allowable deviation of the width of the steel strip (sheet) supplied within the range shall be 0 2 mm.
Table 6 The allowable deviation of the width of the strip after the strip (sheet) is mm
Nominal width width tolerance a
≤150
-0.2
>150~400
-0.3
>400~750
-0.5
>750
-0.6
a By agreement, it can be positive deviation.
7.2.3 sickle bend
For steel strips (sheets) with a width greater than 150 mm, the boring curve should be measured. The knives of any steel strip (sheet) with a length of.2000 mm should not exceed
0.90mm.
7.2.4 Unevenness
For steel strips (sheets) with a width greater than 150 mm, the unevenness shall be measured and the unevenness shall not exceed 1.5%.
7.2.5 residual curvature
According to the requirements of the purchaser, and in the contract, the steel strip (sheet) with a width greater than 150mm can detect the residual curvature, and the bottom of the test steel sheet is tested.
The distance between the side and the support plate should not exceed 35mm.
7.2.6 burr height
The shear burr height of the trimmed steel strip (sheet) should not exceed 0.025 mm.
7.3 Technical characteristics
7.3.1 Density
The agreed density for calculating the magnetic properties and the stacking factor is 7.65 kg/dm3.
7.3.2 Stacking factor
The minimum stacking factor of the steel strip (sheet) shall comply with the requirements of Table 2, Table 3 and Table 4.
7.3.3 Number of bends
The minimum number of bending of the steel strip (sheet) parallel to the rolling direction is not less than one.
7.3.4 Deviation of shear edges caused by internal stress
The steel strip (sheet) should minimize the occurrence of internal stress. According to the requirements of the purchaser and stated in the contract, materials with a width of not less than 500mm can be used.
The material (the material after slitting and slitting) is tested for the deviation of the sheared edge caused by the internal stress, and the gap measurement value should not exceed 1 mm.
7.3.5 Coating insulation resistance
According to the requirements of the purchaser, the insulation resistance of the coating can be tested after consultation between the supplier and the buyer. And indicate the surface insulation resistance of the coating in the contract.
Or the minimum value of the interlayer resistance. If the steel strip (sheet) needs to be heat treated, it shall be carried out according to the conditions specified by the manufacturer and marked in the contract in the heat.
The coating insulation resistance was measured before or after the treatment.
Note. The insulation resistance of the coating is divided into surface insulation resistance and interlayer resistance.
8 Inspection and testing
8.1 General requirements
8.1.1 When signing the order agreement according to this part, the user may carry out the specified inspection and test or non-regulated inspection and test according to the provisions of GB/T 17505.
Test. However, for non-regulated inspections and tests, the manufacturer shall provide the ratio of total loss and magnetic polarization of the supplied steel strip (sheet).
8.1.2 When ordering according to the regulations and testing, the user shall specify the type of inspection documents in GB/T 18253.
8.1.3 Steel strips shall be batched according to the volume group, generally consisting of one volume to form an acceptance batch.
8.1.4 Unless otherwise agreed, the provisions of 8.1.3 apply to shear edge deviations due to internal stresses, shear adaptability, coating insulation resistance,
Inspection of geometric characteristics and tolerances.
8.1.5 When the product is supplied in the form of a sub-volume, the test results on the original acceptance group shall apply to the sub-volume.
8.2 Sampling
8.2.1 General requirements
8.2.1.1 Sampling shall be taken from each of the acceptance groups.
8.2.1.2 The innermost and outermost rings of the coil shall be regarded as packaging materials and do not represent the quality of the entire coil. The specimen shall not be taken from this part. Sample
Avoid welds and joint areas.
8.2.1.3 The same pair of specimens can be used to test a variety of characteristics by reasonably arranging the test sequence.
8.2.2 Magnetic properties
8.2.2.1 Magnetic properties test specimens shall be sampled longitudinally parallel to the rolling direction. Specific requirements are as follows.
a) When testing with a 25cm Epstein square, a sample consists of 4 times the sample, and the recommended weight is about 0.50kg.
The sampling method, size and allowable deviation shall comply with the provisions of GB/T 3655; before the test, the sample shall be provided under the conditions provided by the manufacturer.
Perform stress relief annealing.
b) When testing with a single-chip tester, the sampling method, size and tolerance of the sample shall comply with the provisions of GB/T 13789.
8.2.2.2 When testing the maximum specific loss of the aged steel strip (sheet) aging specimen, the aged specimen shall be kept at a temperature of 225 ° C ± 5 ° C for 24 h.
Then air cool to ambient temperature.
8.2.3 Geometric characteristics and deviations
8.2.3.1 Test steel strip (sheet) thickness, width, unevenness and boring bending specimen is.2000mm long steel strip or a steel sheet.
8.2.3.2 Test the residual curvature of the steel strip (sheet) The length of the specimen is 500mm, the width is the width of the supplied steel strip (sheet), and the length of the specimen
The line should be parallel to the rolling direction.
8.2.3.3 The test burr height sample is taken from the steel strip (sheet) delivered by the finished product. The recommended sample length is not less than 500 mm.
8.2.4 Technical characteristics
8.2.4.1 Stacking factor
Test specimens of steel strip (sheet) stacking factor shall be of sufficient size to be stacked with specimens of at least 6 mm height. In case of dispute, try
The sample should consist of 100 pieces. The sample has a minimum width of 20 mm and a minimum surface area of 5000 mm 2 . The width and length deviation of the sample is less than or equal
At ±0.1mm. The sample should have no obvious burrs before the test.
8.2.4.2 Number of bends
Test specimens for the number of bending of steel strips (sheets) shall comply with the provisions of A.1.
8.2.4.3 Deviation of shear edges caused by internal stress
The test piece for measuring the deviation of the sheared edge caused by the internal stress of the steel strip (sheet) is a 1000 mm long steel strip or steel sheet.
8.2.4.4 Coating insulation resistance
Samples for testing the insulation resistance of steel strip (sheet) coating shall be sampled according to the provisions of GB/T 2522-2007.
8.3 Test methods
8.3.1 General requirements
For each characteristic specified, each acceptance b...
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