GB/T 2521.2-2025 Cold-rolled electrical steel delivered in the fully-processed state - Part 2: Grain-oriented steel strip (sheet)
1 Scope
This document defines the classification, symbols and designations, general requirements, technical requirements, inspection and testing, judgment and reinspection rules, packaging, marking and quality certificates, order contents of cold-rolled grain-oriented electrical steel strip (sheet) in nominal thicknesses of 0.18mm, 0.20mm, 0.23mm, 0.27mm, 0.30mm and 0.35mm, with both sides coated with insulating coating.
This document is applicable to cold-rolled grain-oriented electrical steel strip (sheet) delivered in the fully-processed state, and intended for the construction of magnetic circuits.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 2522 Methods of test for the determination of coating insulation resistance and coating adhesion of electrical strip and sheet (GB/T 2522-2017, IEC 60404-11:2012, NEQ)
GB/T 2900.60 Electrotechnical terminology - Electromagnetism [GB/T 2900.60-2002, eqv IEC 60050(121):1998)
GB/T 3655 Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of an Epstein frame (GB/T 3655-2022, IEC 60404-21996, MOD)
GB/T 9637 Electrotechnical terminology - Magnetic materials and components [GB/T 9637-2001, eqv IEC 60050(221):1990]
GB/T 13789-2022 Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet tester (GB/T 13789-2022, IEC 60404-3:1992, MOD)
GB/T 17505 Steel and steel products - General technical delivery requirements (GB/T 17505-2016, ISO 404:2013, MOD)
GB/T 18253 Steel and steel products - Types of inspection documents (GB/T 18253-2018, ISO 10474:2013, IDT)
GB/T 19289 Methods of measurement of resistivity, density and stacking factor of electrical steel strip and sheet (GB/T 19289-2019, IEC 60404-13:2018, IDT)
YB/T 4292 Methods of determination of the geometrical characteristics of electric steel sheet and strip (YB/T 4292-2012, IEC 60404-9:1987, MOD)
YB/T 4731 Reverse bend test of electric steel sheet and strip (YB/T 4731-2019, IEC TR 63114:2018, IDT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.60 and GB/T 9637 apply.
4 Classification
4.1 The grades of steel strips (sheets) are classified according to their nominal thickness (0.18mm, 0.20mm, 0.23mm, 0.27mm, 0.30mm and 0.35mm) and the maximum specific total loss P1.7/50 at a magnetic polarization of 1.7T and a frequency of 50Hz, and are further subdivided into conventional grade, high magnetic polarization grade, non-heatproof magnetic domain refined grade and heatproof magnetic domain refined grade.
4.2 Steel strips (sheets) are classified as trimmed or untrimmed ones depending on delivery conditions.
5 Symbols and designations
5.1 See Table 1 for symbols used in this document and their corresponding descriptions.
Table 1 Symbols and descriptions
Symbol Unit Description
P W/kg Specific total loss, usually called iron loss
P1.5/50 W/kg The specific total loss measured at a magnetic polarization of 1.5T and a frequency of 50Hz
P1.5/60 W/kg The specific total loss measured at a magnetic polarization of 1.5T and a frequency of 60Hz
P1.7/50 W/kg The specific total loss measured at a magnetic polarization of 1.7T and a frequency of 50Hz
P1.7/60 W/kg The specific total loss measured at a magnetic polarization of 1.7T and a frequency of 60Hz
H A/m Magnetic field intensity
J T Magnetic polarization
J800 T The magnetic polarization at a magnetic field intensity H of 800A/m (expressed as a peak value)
B T Magnetic induction intensity
μ0 H/m Vacuum permeability, taken as 4π×10-7
Fc - The coefficient for converting the specific total loss value tested by SST current method into the value tested by Epstein frame method
5.2 The steel designation comprises the following in the order given:
a) One hundred times the nominal thickness of the material (mm);
b) The characteristic letter:
——"S" for conventional grade of grain-oriented electrical steel;
——"P" for high magnetic polarization grade of grain-oriented electrical steel;
——"R" for non-heatproof magnetic domain refined grade of grain-oriented electrical steel;
——"HR" for heatproof magnetic domain refined grade of grain-oriented electrical steel.
c) One hundred times the maximum specific total loss P1.7/50 (W/kg).
Example:
30S130 for cold-rolled grain-oriented electrical steel strip (sheet) of conventional grade with a nominal thickness of 0.30mm and a maximum specific total loss P1.7/50 of 1.30W/kg;
30P105 for cold-rolled grain-oriented electrical steel strip (sheet) of high magnetic polarization grade with a nominal thickness of 0.30mm and a maximum specific total loss P1.7/50 of 1.05W/kg;
23R085 for cold-rolled grain-oriented electrical steel strip (sheet) of non-heatproof magnetic domain refined grade with a nominal thickness of 0.23mm and a maximum specific total loss P1.7/50 of 0.85W/kg;
23HR080 for cold-rolled grain-oriented electrical steel strip (sheet) of heatproof magnetic domain refined grade with a nominal thickness of 0.23mm and a maximum specific total loss P1.7/50 of 0.80W/kg.
5.3 For a comparison of steel designations between this document, IEC 60404-8-7:2020 and GB/T 2521.2-2016, refer to Annex C.
6 General requirements
6.1 Production process
The production process of the steel strip (sheet) and its chemical composition are left to the discretion of the manufacturer.
6.2 Form of supply
Products are supplied in coils in the case of strips or in boxes in the case of sheets, with detailed requirements as follows:
a) The mass of the coils or boxes shall meet the order requirements. The mass of steel coils is generally 2t to 10t;
b) The inner diameter of steel coils shall be 500mm to 520mm, wherein, 508mm is recommended;
c) The side faces of superimposed steel sheets shall be flat and approximately perpendicular to the top face;
d) Steel coils shall be tightly wound from steel strips of uniform width in order that they do not collapse under their own weight, and the side faces of the coils shall be as straight as possible;
e) Steel strips may exhibit interleaves or welds resulting from the removal of defects. Such interleaves or welds shall be marked, and the steel strip sections before and after the interleaves or welds shall be of the same designation;
f) The number of interleaves or welds shall not exceed 2. The length of the steel strip before and after each interleave or weld shall be at least 200m, and the welds shall be smooth without affecting subsequent processing of the material.
6.3 Delivery condition
Contents
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Symbols and designations
6 General requirements
7 Technical requirements
8 Inspection and testing
9 Judgment and reinspection rules
10 Packaging, marking and quality certificate
11 Ordering information
Annex A (Informative) Comparison between this document and IEC 60404-8-7:2020 in terms of clause/subclause numbers
Annex B (Informative) Technical differences between this document and IEC 60404-8-7:2020 and their causes
Annex C (Informative) Comparison of designations between this document and IEC 60404-8-7:2020, GB/T 2521.2-2016
Bibliography
Standard
GB/T 2521.2-2025 Cold-rolled electrical steel delivered in the fully-processed state—Part 2: Grain-oriented steel strip(sheet) (English Version)
Standard No.
GB/T 2521.2-2025
Status
valid
Language
English
File Format
PDF
Word Count
12500 words
Price(USD)
375.0
Implemented on
2026-3-1
Delivery
via email in 1 business day
Detail of GB/T 2521.2-2025
Standard No.
GB/T 2521.2-2025
English Name
Cold-rolled electrical steel delivered in the fully-processed state—Part 2: Grain-oriented steel strip(sheet)
GB/T 2521.2-2025 Cold-rolled electrical steel delivered in the fully-processed state - Part 2: Grain-oriented steel strip (sheet)
1 Scope
This document defines the classification, symbols and designations, general requirements, technical requirements, inspection and testing, judgment and reinspection rules, packaging, marking and quality certificates, order contents of cold-rolled grain-oriented electrical steel strip (sheet) in nominal thicknesses of 0.18mm, 0.20mm, 0.23mm, 0.27mm, 0.30mm and 0.35mm, with both sides coated with insulating coating.
This document is applicable to cold-rolled grain-oriented electrical steel strip (sheet) delivered in the fully-processed state, and intended for the construction of magnetic circuits.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 2522 Methods of test for the determination of coating insulation resistance and coating adhesion of electrical strip and sheet (GB/T 2522-2017, IEC 60404-11:2012, NEQ)
GB/T 2900.60 Electrotechnical terminology - Electromagnetism [GB/T 2900.60-2002, eqv IEC 60050(121):1998)
GB/T 3655 Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of an Epstein frame (GB/T 3655-2022, IEC 60404-21996, MOD)
GB/T 9637 Electrotechnical terminology - Magnetic materials and components [GB/T 9637-2001, eqv IEC 60050(221):1990]
GB/T 13789-2022 Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet tester (GB/T 13789-2022, IEC 60404-3:1992, MOD)
GB/T 17505 Steel and steel products - General technical delivery requirements (GB/T 17505-2016, ISO 404:2013, MOD)
GB/T 18253 Steel and steel products - Types of inspection documents (GB/T 18253-2018, ISO 10474:2013, IDT)
GB/T 19289 Methods of measurement of resistivity, density and stacking factor of electrical steel strip and sheet (GB/T 19289-2019, IEC 60404-13:2018, IDT)
YB/T 4292 Methods of determination of the geometrical characteristics of electric steel sheet and strip (YB/T 4292-2012, IEC 60404-9:1987, MOD)
YB/T 4731 Reverse bend test of electric steel sheet and strip (YB/T 4731-2019, IEC TR 63114:2018, IDT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.60 and GB/T 9637 apply.
4 Classification
4.1 The grades of steel strips (sheets) are classified according to their nominal thickness (0.18mm, 0.20mm, 0.23mm, 0.27mm, 0.30mm and 0.35mm) and the maximum specific total loss P1.7/50 at a magnetic polarization of 1.7T and a frequency of 50Hz, and are further subdivided into conventional grade, high magnetic polarization grade, non-heatproof magnetic domain refined grade and heatproof magnetic domain refined grade.
4.2 Steel strips (sheets) are classified as trimmed or untrimmed ones depending on delivery conditions.
5 Symbols and designations
5.1 See Table 1 for symbols used in this document and their corresponding descriptions.
Table 1 Symbols and descriptions
Symbol Unit Description
P W/kg Specific total loss, usually called iron loss
P1.5/50 W/kg The specific total loss measured at a magnetic polarization of 1.5T and a frequency of 50Hz
P1.5/60 W/kg The specific total loss measured at a magnetic polarization of 1.5T and a frequency of 60Hz
P1.7/50 W/kg The specific total loss measured at a magnetic polarization of 1.7T and a frequency of 50Hz
P1.7/60 W/kg The specific total loss measured at a magnetic polarization of 1.7T and a frequency of 60Hz
H A/m Magnetic field intensity
J T Magnetic polarization
J800 T The magnetic polarization at a magnetic field intensity H of 800A/m (expressed as a peak value)
B T Magnetic induction intensity
μ0 H/m Vacuum permeability, taken as 4π×10-7
Fc - The coefficient for converting the specific total loss value tested by SST current method into the value tested by Epstein frame method
5.2 The steel designation comprises the following in the order given:
a) One hundred times the nominal thickness of the material (mm);
b) The characteristic letter:
——"S" for conventional grade of grain-oriented electrical steel;
——"P" for high magnetic polarization grade of grain-oriented electrical steel;
——"R" for non-heatproof magnetic domain refined grade of grain-oriented electrical steel;
——"HR" for heatproof magnetic domain refined grade of grain-oriented electrical steel.
c) One hundred times the maximum specific total loss P1.7/50 (W/kg).
Example:
30S130 for cold-rolled grain-oriented electrical steel strip (sheet) of conventional grade with a nominal thickness of 0.30mm and a maximum specific total loss P1.7/50 of 1.30W/kg;
30P105 for cold-rolled grain-oriented electrical steel strip (sheet) of high magnetic polarization grade with a nominal thickness of 0.30mm and a maximum specific total loss P1.7/50 of 1.05W/kg;
23R085 for cold-rolled grain-oriented electrical steel strip (sheet) of non-heatproof magnetic domain refined grade with a nominal thickness of 0.23mm and a maximum specific total loss P1.7/50 of 0.85W/kg;
23HR080 for cold-rolled grain-oriented electrical steel strip (sheet) of heatproof magnetic domain refined grade with a nominal thickness of 0.23mm and a maximum specific total loss P1.7/50 of 0.80W/kg.
5.3 For a comparison of steel designations between this document, IEC 60404-8-7:2020 and GB/T 2521.2-2016, refer to Annex C.
6 General requirements
6.1 Production process
The production process of the steel strip (sheet) and its chemical composition are left to the discretion of the manufacturer.
6.2 Form of supply
Products are supplied in coils in the case of strips or in boxes in the case of sheets, with detailed requirements as follows:
a) The mass of the coils or boxes shall meet the order requirements. The mass of steel coils is generally 2t to 10t;
b) The inner diameter of steel coils shall be 500mm to 520mm, wherein, 508mm is recommended;
c) The side faces of superimposed steel sheets shall be flat and approximately perpendicular to the top face;
d) Steel coils shall be tightly wound from steel strips of uniform width in order that they do not collapse under their own weight, and the side faces of the coils shall be as straight as possible;
e) Steel strips may exhibit interleaves or welds resulting from the removal of defects. Such interleaves or welds shall be marked, and the steel strip sections before and after the interleaves or welds shall be of the same designation;
f) The number of interleaves or welds shall not exceed 2. The length of the steel strip before and after each interleave or weld shall be at least 200m, and the welds shall be smooth without affecting subsequent processing of the material.
6.3 Delivery condition
Contents of GB/T 2521.2-2025
Contents
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Symbols and designations
6 General requirements
7 Technical requirements
8 Inspection and testing
9 Judgment and reinspection rules
10 Packaging, marking and quality certificate
11 Ordering information
Annex A (Informative) Comparison between this document and IEC 60404-8-7:2020 in terms of clause/subclause numbers
Annex B (Informative) Technical differences between this document and IEC 60404-8-7:2020 and their causes
Annex C (Informative) Comparison of designations between this document and IEC 60404-8-7:2020, GB/T 2521.2-2016
Bibliography
