GB/T 2521-1996 Cold-rolled grain-oriented and non-oriented magnetic steel strip (sheet)
Some standard content:
GB/T 2521—1996
This standard adopts the international standards IEC404-8-7 (1988) "Technical Conditions for Grain-Oriented Magnetic Steel Sheets (Strips)" and IEC 404-8-4 "Technical Conditions for Rolled Non-Oriented Magnetic Steel Sheets (Strips)". Except for the iron loss values of 30QG110, 30QG120, and 50W540 grades, which are 1.10, 1.20, and 5.40W/kg respectively, and the iron loss values of the corresponding grades in the IEC standard are 1.11, 1.17, and 5.30W/kg respectively, the iron loss and magnetic induction intensity values of other grades are equivalent to the IEC standard. There are 17 more grades than the IEC standard.
The iron loss values of most grades in this standard are lower than those of the corresponding grades in the original standard GB2521-88. For example, the iron loss value of 35Q135 is reduced from 1.37W/kg in the original standard to 1.35W/kg. There are 7 more grades than the original standard GB2521-88. The representation method of each grade moves the value indicating thickness to the front and removes \D\, such as: DW 310-50 is changed to 50W310, and the rest are analogous. The grade difference of each brand is changed from the original non-ratio grade difference to the ratio grade difference, and the last digit is *0\ or *5". Since there is a national standard for magnetic test method, Appendix A in the original standard is removed, and GB/T13789, GB/T2522, and GB/T3655 standards are directly quoted. From the date of entry into force of this standard, the national standard GB2521-88 is invalid. This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Steel Standardization. The drafting unit of this standard: Wuhan Iron and Steel (Group) Corporation. The main drafters of this standard: Yang Chunfu, Ke Shixuan, Peng Yuanjun. This standard was first issued in 1981 and revised for the first time in February 1988. This is the second revision. 1 Scope
National Standard of the People's Republic of China
Cold-rolled grain-oriented and non-oriented magnetic steel strip (sheet)
GB/T 2521-—1996
Replaces GB2521—88
This standard specifies the grade, magnetic properties, size, shape, mechanical properties, process characteristics and inspection methods of grain-oriented and non-oriented magnetic steel strips (sheets).
This standard applies to fully cold-rolled oriented and non-oriented magnetic steel strips (sheets) with insulating coatings used in magnetic circuit structures. 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T228—87 Metal Tensile Test Methods
GB/T 235-88 Metal repeated bending test method (thickness equal to or less than 3mm thin plate and strip) GB/T247-88 General provisions for acceptance, packaging, marking and quality certificate of steel plates and strips GB/T2522-88 Test method for interlayer resistance, coating adhesion and mounting coefficient of electrical steel sheets (strips) GB/T3076-82 Tensile test method for metal sheets (strips) GB/T3655-92 Measurement method for magnetic, electrical and physical properties of electrical steel sheets (strips) GB/T6397-86 Metal tensile test specimens GB/T13789-92 Measurement method for magnetic properties of single electrical steel sheets (strips) 3 Definitions and designation methods
3.1 Definitions
3.1.1 Standard specific total iron loss (standard Specifie total loss) When the magnetic induction intensity changes with time according to the sine law, its peak value is a certain calibration value, and the frequency of change is a certain ~ calibration frequency, the power consumed by the unit mass of the iron core at a temperature of 20°C is defined as the standard total iron loss (referred to as standard iron loss or iron loss), and the unit is W/kg. 3.1.2 Standard magnetic induction intensity (standard magnetic induction intensity) The temperature is 20°C, the core sample is from the demagnetized state, and the magnetic induction intensity changes according to the stop-sinusoidal law at the calibration frequency. When the peak value of the AC magnetic field reaches a certain calibration value, the peak value of the magnetic induction of the core sample is the standard magnetic induction intensity (referred to as magnetic induction intensity or magnetic induction), and the unit is T. 3.1.3 Number of bends (uamlerafbends) The number of bends is the number of repeated bends observed by the naked eye before the first crack appears on the base metal. It represents the ductility of the material. 3.2 Method of indicating grades
Approved by the State Administration of Technical Supervision on September 27, 1996 and implemented on March 1, 1997
4 Classification
GB/T2521—1996
Indicates iron loss, and the number is 100 times the base value. Indicates high magnetic induction materials in oriented steel.
Letter Q: Indicates oriented steel strip (sheet).
Letter W: Indicates non-oriented steel strip (sheet).
Indicates nominal thickness, and the number is 100 times the nominal thickness. The magnetic steel strip (sheet) in this standard is divided into two categories: oriented and non-oriented. Each category is divided into different grades according to the maximum iron loss and the nominal thickness of the material.
5 Technical requirements
5.1 Magnetic properties
5.1.1 Magnetic induction
When the oriented steel is subjected to an alternating magnetic field of 800A/m (peak value) and a frequency of 50Hz, the specified minimum magnetic induction value Bc (peak value) shall comply with the provisions of Table 1.
When the non-oriented steel is subjected to an alternating magnetic field of 5000A/m (peak value) and a frequency of 50Hz, the specified minimum magnetic induction value Bom (peak value) shall comply with the provisions of Table 2.
5.1.2 Iron loss
When the magnetic induction is 1.7T and the frequency is 50Ha, the specified maximum iron loss P1., of oriented steel shall comply with the provisions of Table 1. When the magnetic induction is 1.5T and the frequency is 50Hz, the specified maximum iron loss P1.5 of non-oriented steel shall comply with the provisions of Table 2. Table 1 Take the steel magnetic properties and process characteristics
27QG100
27QG110
27Q120
27Q130
270140
30QG110
30QG120
30QG130
30Q130
30Q140
30Q150
Nominal thickness
Theoretical density
Maximum iron loss
Minimum magnetic induction
Minimum number of bending
Minimum stacking coefficient
35QG125
35QG135
35Q135
35Q145
35Q155
35Q165
Nominal thickness
GB/T2521—1996
Table 1 (end)
Theoretical density
kg/dms
Maximum iron loss
Minimum magnetic induction
Minimum number of Liqu
Minimum stacking coefficient
①When tested according to CB/T3655, the sample should be stress-relieved annealed. The annealing process is: keep it at a furnace temperature of 800±20C for 2h, and then air-cool it to room temperature.
When tested according to GB/T13789, the sample may not be stress-relieved annealed. Table 2 Non-oriented magnetic properties and process characteristicswww.bzxz.net
35W230
35W250
35W270
35w300
35W330
35w360
35W400
Nominal thickness
Theoretical density
Maximum iron loss
Minimum magnetic induction
Minimum Li Quci rescue
Minimum stacking coefficient
50W230
50W251
50W270
5CW310
50W3343
50W350
50W400
50W470
5rw540
5CW600
50W700
50W800
50W1000||t t ||50W1300 |1 Thickness
Nominal thickness
GB/T 2521—1996
Table 2 (Complete)
Theoretical density
Maximum iron absorption
Minimum ether sensitivity
Minimum bending coefficient
Minimum stacking coefficient
The thickness tolerance of the steel strip measured shall not be less than 15mm from the edge, and the transverse thickness difference, the steel strip with inter-orientation shall comply with the provisions of Table 3, and the steel strip without inter-orientation shall comply with the provisions of Table 4.
5.2.2 Width
The steel strip is delivered with trimmed edges. The width tolerance of the steel strip delivered with trimmed edges shall comply with the provisions of Table 3, and the steel strip without orientation shall comply with the provisions of Table 4.
According to the user's requirements, after the agreement between the supply and demand parties, the steel strip without orientation may also be delivered without trimming. 5.2.3 Length
The length refers to the length of the steel sheet cut from the steel strip. The length of steel sheet is generally 2000mm, and it can be multiple of the width upon agreement between the supplier and the buyer. The allowable deviation of the length of oriented steel sheet is in accordance with the provisions of Table 3 and Table 4 respectively. Nominal width
≥150~100
400~750
Nominal width
150~-500
>500-1000
Nominal thickness
Nominal thickness
5.2.4 Unevenness (flatness)
GB/T 2521—1996
Table 3 Allowable deviation of dimensions of oriented steel strip (sheet) Allowable thickness
Transverse thickness difference
Allowable width deviation
Table 4 Allowable deviation of dimensions of non-oriented strip (sheet) Allowable thickness deviation
Transverse thickness difference
The unevenness of steel sheet shall not exceed 1.5% for oriented steel and not exceed 2.0% for non-oriented steel. 5.2.5 Sickle
The sickle of the steel strip shall not exceed 1.0 mm for every 2 000 mm. 5.2.6 Burr
Allowable deviation in width
Allowable deviation in length
Allowable deviation in length
The burr of the steel strip (sheet) shall not exceed 0.05 mm. For the steel strip (sheet) delivered in strips, it shall not exceed 0.10 mm. 5.3 Mechanical properties
According to the requirements of the purchaser and the agreement between the supply and demand parties, the mechanical properties of the non-oriented steel strip (sheet) shall comply with the provisions of Table 5. Brand
35W230
35W2 50
35W270
35W300
33W330
35W360
35W400
35W440
50W230
50W250
50W270
5/W290
SuW310
5cw330
5cw350
Tensile strength.
Not less than
GB/T 2521—1996
Table 5 Mechanical properties of non-oriented steel strip (sheet)
Elongation
Note: Strip (sheet) thickness is less than 0.50 mm + elongation is 8; when the thickness of the steel strip (sheet) is equal to or less than 0.50mm, the elongation is 8: 5.4 Process characteristics
5.4.1 Density
50W400
50W540
50w600
50W700
50W800
S0W1000
65W600
65W800
65W1000
65W1300
65W1600
The density values in Table 1 and Table 2 are parameters for measuring magnetism and stacking coefficient. 5.4.2 Stacking coefficient
The stacking coefficient shall comply with the provisions of Table 1 and Table 2. 5.4.3 Bending times
Tensile strength
Not less than
Elongation
The minimum bending times of longitudinal specimens of oriented steel strips (sheets) shall comply with the provisions of Table 1. The minimum bending times of transverse specimens of non-oriented steel strips (sheets) shall comply with the provisions of Table 2.
5.4.4 Insulating coating
All grades of steel strips (sheets) shall be coated with insulating coating. The insulating coating shall be resistant to corrosion by insulating paint, transformer oil, machine oil, etc. and have good adhesion.
The insulating coating of oriented steel shall be able to undergo stress relief annealing. The minimum resistance value of the insulating coating of the steel sheet measured before and after stress relief annealing shall comply with the agreement between the supplier and the buyer as much as possible. 6 General requirements
6.1 Supply form
6.1.1Steel sheets shall be supplied in boxes and steel strips shall be supplied in coils. The weight of boxes and coils shall comply with the order agreement. If there is no special requirement in the agreement, the weight of the box and coil shall not exceed 3t, and the inner diameter of the steel coil shall be 510mm20mm. 6.1.2 In principle, each roll of steel strip is rolled up by one steel strip. Individual rolls are allowed to be rolled up by more than two steel strips of the same brand and size. GB/T 2521-1996
Each strip shall be not less than 200m long, and the middle joint shall be butt-jointed, and shall be clearly marked. 6.1.3 When the steel coil is wound, the edges shall be rolled neatly and fully tightened, and shall not collapse under its own weight. 6.2 Surface quality
6.2. 1 The surface of the steel strip (sheet) shall be smooth and shall not have defects such as rust, pores, heavy skin, folds, bubbles, and delamination that hinder its use. If the steel strip has a small amount of the above defects that cannot be removed, it can be delivered with defects, but it shall be marked. 6-2.2 The surface of the steel strip (sheet) is allowed to have defects that do not affect the use, such as coating streaks, scratches, poor steel quality without peeling, and a small amount of scars, pits, pits, bulges and scratches within the thickness deviation range. 6-2.3 The insulating coating should have good adhesion and should not fall off significantly when cutting and winding. 7 Inspection
7.1 Overview
In the supply contract signed according to this standard, the inspection items refer to the iron loss and magnetic induction listed in Table 1 and Table 2. If there are special inspection items, they should be indicated in the contract.
Generally, one production roll is an acceptance batch: when the product is delivered in longitudinally cut rolls or rolls cut into sheets, the acceptance performance provided is the test result on the production roll batch. 7.2 Sample selection
Test samples should be taken for each acceptance batch. The samples should be cut from the inner and outer rings of the steel coil at a distance of not less than 3m from the end. By arranging the test sequence reasonably, the same set of samples can be used to test different characteristics. 7.3 Sample preparation
7.3.1 Magnetic sample
The preparation of magnetic sample shall comply with the provisions of GB/T3655 or GB/T13789 respectively. 7.3.2 Mechanical properties sample
For steel strip (sheet) with thickness less than T0.50mm, the test sample shall comply with the provisions of GB/T3076. For steel strip (sheet) with thickness greater than or equal to 0.50mm, the test sample shall comply with the provisions of GB/T6397. 7.3.3 Process characteristics
7.3.3.1 Stacking coefficient sample
The test sample shall comply with the provisions of GB/T2522. 7.3.3.2 Bending number sample
The sampling position is the same as 7.2. The low edge cannot be taken as the test sample. For oriented steel strip (sheet), take two 30mm×300mm longitudinal samples. For non-oriented steel strip (sheet), take two 30mm×300mm transverse samples. The specimen should be prevented from deformation and kept flat. 7.3.3.3 Aging
Non-oriented specimens are heated in a furnace at 200℃ for 48h. Oriented specimens are heated in a furnace at 150C for 120h. The iron loss value after aging should also meet the requirements of Table 1 and Table 2.
Note: Whether aging is determined by the supplier based on the carbon content. 7.4 Test method
For each specified characteristic, each acceptance batch (roll) should be tested. The test temperature is 23℃±5℃, and the relative density is less than 80%. 7.4.1 Iron loss and magnetic induction
The test of iron loss and magnetic induction can be tested according to GB/T13789 or GB/T3655. If tested according to GB/T3655, it is allowed to use 0.5kg square chart for testing, and the sample weight is about 0.5kg. The iron loss and magnetic induction values tested should be accurate to 2 decimal places. If the third digit of the iron loss value is not zero, it will be rounded up, and if the magnetic induction value is not zero, it will be removed. 7.4.2 Dimensions and appearance
7.4.2.1 Thickness and length
The thickness of the steel strip (sheet) is measured with a micrometer with an accuracy of 0.01 mm at any place not less than 15 mm from the edge. The length of the steel sheet is measured parallel to the center line. 7.4.2.2 Width
GB/T 2521—1996
The width is measured perpendicular to the center line of the steel strip (sheet) 7.4.2.3 Unevenness
Put the steel sheet freely on the platform, and do not apply any pressure except the weight of the steel sheet itself. Use a ruler to measure the height h and wavelength L of the maximum wave (full wave). The unevenness is equal to (/L)×100%. 7.4.2.4 Sickle
Use a ruler to close the concave side of the steel strip and measure the maximum distance between the ruler and the concave side. 7.4.2.5 Burr height
Use a micrometer to measure the thickness of the steel strip (sheet) at the cut and the inner side of the steel strip (sheet), and calculate the burr height based on the difference in thickness between the two. 7.4.3 Mechanical properties
The tensile strength and elongation of steel strips (sheets) with a thickness of less than 0.50 mm shall be tested in accordance with GB/T 3076, and the tensile strength and elongation of steel strips (sheets) with a thickness of greater than or equal to 0.50 mm shall be tested in accordance with GB/T228. 7.4.4 Process characteristics
7.4.4. 1 Stacking coefficient
The test of stacking coefficient shall be carried out in accordance with GB/T2522. 7.4.4.2 Interlayer resistance and adhesion
The test of interlayer resistance and adhesion shall be carried out in accordance with GB/T2522, 7.4.4.3 Bending number
The test of bending number shall be carried out in accordance with GB/T235, and the minimum value of the two specimens shall be taken as the test result. 7.5 Re-inspection
The re-inspection rules shall comply with the provisions of GB/T 247. 8 Packaging, marking and quality certificate
8.1 Packaging, marking
The packaging and marking of steel strips (sheets) shall comply with the provisions of GB/T247. 8.2 Quality certificate
The delivered steel strips (sheets) shall be accompanied by a quality certificate, which shall indicate; Standard number:
Supplier name (or factory mark);
Buyer name!
Contract number:
Roll, box number:
Product name, brand, size;
Weight:
Deduction weight when there are defects in the steel;
Magnetic properties and other test results specified in the agreement.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.