GB/T 14991-1994 Deformed Permanent Magnetic Steel GB/T14991-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Deformable permanent-magnet steels
Deforimable permanent-magnet steelsGB/R14991:-94
Replaces GBA174-82
This standard applies to deformed permanent-magnet steels used in the production of water-permanent magnets, including cold-rolled strips, hot-rolled (forged) bars and flats of 2J63-2161 permanent-magnet steels, and hot-rolled (forged) bars and flats of 2J65 and 2J67 water-magnet steels. 1 Dimensions and appearance
1.1 Dimensions and allowable deviations
1.1.1 The dimensions and allowable deviations of hot-rolled (forged) bars shall comply with the provisions of Table 1. Table 1
31 ~ 45
>45 ~70
>70~100
Allowable deviation of true diameter
Not less than
10 ~20
>20 ~ 30
1.1.2 The dimensions and allowable deviations of hot-rolled flat products shall comply with the provisions of Table 2. Table 2
>6 ~15
>15~20
>20~25
Allowable deviation of thickness
1.1. The dimensions and allowable deviations of cold-rolled strip products shall comply with the provisions of Table 3. Approved by the State Bureau of Technical Supervision on April 4, 1994 Width
20~100
Diameter tolerance
Not small
Width tolerance
Implementation on May 1, 1994.40~0.60
>0.60~0.80
2>0.80~1.00
>1.00~1.50
1.50~2,00
2.0U~2.50
>2.50~3.00
GH/T 14991-94
Thickness tolerance
- 0,11
40~120
Width tolerance
No edge
1.1.4 According to the requirements of the buyer, the bar, flat and strip materials with dimensions other than those in Tables 1, 2 and 3 can be provided after negotiation between the supplier and the buyer. 1.2 Appearance
1.2.1 The roundness of the bar should not exceed 75% of the dimensional tolerance. 110
Bars should be delivered in point strips. The local curvature of the bar shall not exceed 6mm per meter. The total curvature of the entire length of the bar shall not exceed 10.6% of the total length.
1.2.2 Strips with a thickness of less than or equal to 1.0mm should be delivered with trimmed edges. Strips with a thickness of more than 1.0mm should be delivered without trimmed edges. Untrimmed strips are allowed to have defects such as cracks on the edges, but the nominal width size must be guaranteed. Cold rolled strips with a thickness less than or equal to 1.5 mm shall be delivered in coils, and those with a thickness greater than 1.5 shall be delivered in straight bars.
1.3 Marking example
The 2163 hot-rolled bar with a diameter of 20 mm is marked as: Hot bar 2J63-$20-GB/T:4#9[-94The 2J65 hot-rolled flat with a thickness of 6 mm and a width of 20 mm is marked as: Hot flat 2J65-6×2(-(:B/T 1459[-94The 2J64 cold-rolled strip with a thickness of 0.5 mm and a width of 50 mm is marked as: Cold strip 2.64-0.5×50-GB/T14991-9↓2 Technical requirements
2.1 Grade and chemical composition
The grade and chemical composition of permanent magnet steel shall comply with the provisions of Table 4. When the performance and hardness meet the requirements of this standard, the chemical composition is allowed to deviate from the requirements of Table 4. Specify scope.
not greater than
0.0300.0200.30
0.95 ~1.10|2. 80 ~3.60
0.0300.020
0.0300.020
0.0250.025bZxz.net
0.68~0.78|| tt||0.30~0.505.20~6.20
0.90~1.055.50~6.50
5.50~6.50
0.20 ~ 0. 40| 0.17 ~ 0. 40
0.20~0, 40) 0.17~0.40
0.20~0.40 0.17 ~0.40
11,0~13.016.5-17,50,10~0.50
2.2 Smelting method
Gn/r14991-:94
Hydromagnetic steel is smelted by electric guanidine furnace or non-vacuum induction furnace, and other smelting methods that can meet the requirements of this standard can also be used. 2.8 Delivery status
Hydromagnetic steel hot-rolled (forged) bars and flats can be delivered with or without heat treatment. Cold-rolled strips are delivered without heat treatment. 2.4 Magnetic properties
2.4.1 After heat treatment, the magnetic properties of permanent magnet steel samples shall meet the requirements of Table 5. When the product of coercivity tlc and residual magnetic induction Br is not less than that specified in Table 5, the coercivity tlc may be reduced by 5%, or the residual magnetic induction Br may be reduced by 10%.
2.4.2 The supplier shall provide the magnetic energy product (BH) max data, but it shall not be used as the basis for assessment. Table 6
Coercivity He
2.5 Hardness
Oe (kA/m)
62 (4.93)
62 (4.93)
100 (7.96)
260 (20.89)
Residual magnetic induction intensity Br
Gs (T)
9500 (0.95)
1000 (1.0)
8500(0.85)
10000 (1.00)
The hardness of hot-rolled (forged) bars and flats delivered after heat treatment shall conform to the provisions of Table 6. Table 6
2.6 Surface quality
Br ·He
Gs· Oe
0.59×10h
0.62×105
Brinell hardness HH not more than
2.6.1 The surface of bars and flats shall not have cracks, folds, grains and burrs. Local defects shall be removed by trimming, and the bar section length after the defects are removed shall be within the allowable deviation range. Individual defects with a depth not exceeding half of the allowable tolerance may not be trimmed if they do not affect the use.
2.6.2 The surface of cold-rolled strips shall be flat, and cracks and interlayers are not allowed. Minor defects that do not affect the use are allowed. 3 Test methods
GB/T 14991-- 94
Test methods for various quality inspections of permanent steel and the sampling location shall comply with the provisions of Table 7. Table?
Inspection rules
Inspection items H
Chemical analysis
Magnetic properties
Surface quality
4.1 Inspection and acceptance
Test method
YB 789—75
YH 35—78
Rock method or linear weight method
GB231—63
Use measuring tools that can ensure accuracy
The inspection and acceptance of permanent magnet steel shall be carried out by the supplier’s technical supervision department. Sampling location
GB22—63
Hot-rolled (forged) material: forged or finished product
Cold-rolled strip: finished product
1 piece per furnace
2 pieces per batch
10% but not less than 2 pieces per batch
4.2 Batch rules
Permanent magnet steel shall be submitted for inspection and acceptance in batches. Each batch shall consist of bars, flats or cold-rolled strips of the same grade, same melting furnace number, same cross-sectional size and processing method. 4:3 Sampling quantity
The sampling quantity for quality inspection of permanent magnet steel shall comply with the provisions of Table 7. 4. *Re-inspection and judgment rules
4.4.1 When the magnetic property test result of permanent magnet steel is unqualified, it is allowed to take two samples for re-inspection. If the re-inspection result is still unqualified, the batch of magnet steel shall not be accepted. However, the supplier may change the heat treatment system and resubmit the products for inspection as a new batch. 4.4.2 When the hardness of the bars or flats of permanent magnet steel is unqualified, it is allowed to reheat treat the batch of steel and submit it for inspection. If it is qualified, it can be delivered.
5 Packaging, marking and quality certificate
The packaging, marking and quality certificate of permanent magnet steel shall comply with the requirements of YH/524293 "General Provisions for Packaging, Marking and Quality Certificate of Precision Alloys".
CB/T14991-94
Appendix A
Preparation and testing of magnetic specimens of permanent magnet steel
(Supplement)
A, 1 The specimen is made into a bar shape, and the length-to-diameter ratio should be greater than or equal to 8. The length-to-diameter ratio of the specimen is allowed to be greater than or equal to 5. The two end faces of the bar specimen should be parallel and perpendicular to the axis. The cross-sectional area of ​​the specimen is consistent along the entire length direction, and its deviation does not exceed 1% of the minimum cross-sectional area. Cold rolled strip samples are cut along the T direction to take strips A with a length of 4mm and a width of 5-8mm. 2 The device for measuring magnetic properties is recommended to use a permeameter. The magnetic field strength applied during the test should comply with the provisions of the following table. Brand
e (kAim)
600 (47.75)
600 (47.75)
1000 (79.58)
2000 (159.16)
GH/T 14991--94
Appendix B
Heat treatment system for permanent magnetic steel samples
(reference)
The heat treatment of deformed water magnetic steel samples is recommended to be carried out using the process listed in the following table. Brand
Additional instructions:
Recommended heat treatment system
(1) 15 fire
(2) Heat at 500~600℃ for 5~15min, then heat to 800~850: keep warm for 1n~15min, oil.
(3) Aging in 100℃ boiling water for 5h
【1）Normalizing at 1200～1250.
(2) Preheat at 500~600℃ for 5-15min, then heat to 800~860: keep warm for 5~15min, oil.
(3) Aging in 100℃ boiling water for 5h(1) 1150～1200℃ fire.
(2) Preheat at 50k)~60℃ for 5~15min, then heat to 93~98℃ and keep warm for 10~15min, oil rate.
(3) Heat in 10 boiling water for more than h
(1) Keep warm at 1250℃ for 15~3h, itchy, (2) Temper at 650~725, keep warm for 1~2h, air cool. This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Shaanxi Iron and Steel Research Institute. The main drafter of this standard was Liu Yushu.
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