GB/T 14990-1994 Iron-cobalt-molybdenum hysteresis alloy hot-rolled (or forged) bars GB/T14990-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Ifot rolled (or forged) bars for iron-cobalt-molybdenum hysteresis alloys This standard applies to hot-rolled (or forged) bars of iron-cobalt-molybdenum alloys for making rotors of hysteresis motors. 1 Dimensions and appearance
1.1 Dimensions and their allowable deviations
GB/T14990-94
Substitute GBn173—82
The dimensions and allowable deviations of hot-rolled (or forged) bars of alloys shall comply with the provisions of Table 1. According to the requirements of the purchaser, after negotiation between the supply and demand parties, bars, flat products and tubes with dimensions other than those in Table 1 may be supplied. Table 1
31 ~ 45
>45 ~ 70
>70~100
1.2 Shape
Diameter allowable deviation
Not less than
The ovality of alloy bars should not exceed 75% of the allowable tolerance. Straight
10 ~20
220～30
Diameter allowable deviation
Not less thanbzxz.net
Alloy bars should be delivered in 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 0.6% of the total length.
1.3 Marking example
2J21 hot forged bar with a diameter of 45mm is marked as: Hot bar 2J21—$45—GB/T 14990-942 Technical requirements
2.1 Grade and chemical composition
The grade and chemical composition of the alloy bar shall comply with the provisions of Table 2. When the hysteresis properties of the alloy bar meet the requirements of this standard, the chemical composition is allowed to deviate from the range specified in Table 2.
Approved by the State Bureau of Technical Supervision on April 4, 1994 and implemented on May 1, 1994
Alloy grade
Refining method
Not more than
Gn/T14990-94
11.0~13.0
10.5~11.5
12.5~13.5
11.0 ~[3,0
14.5 ~15.5
11,0 ~13,016.5 ~17.5
0.10~0.50
0.10~0.50
0,10~0.50
0,10~0.50
Alloy bars are smelted in non-vacuum induction furnace or vacuum induction furnace, or other smelting methods that meet the requirements of this standard. 2.3 Delivery status
Alloy bars are delivered without heat treatment.
2.4 Hysteresis properties
After the alloy bar samples are heat treated, the hysteresis properties shall meet the requirements of Table 3. Table 3
Alloy grade
Hu, Oe
2.5Surface quality
120~160h
180 ~220
220~280
300~360
Hp, Gis
10000~13000
1000013000
900~12000
9000 ~120100
Pμ, erg/cm
Not less than
3.8×10°
The surface of alloy bars shall not have cracks, folds, H and burrs. Local defects shall be removed by trimming, and the cross section of the bars shall be within the allowable deviation range after the defects are eliminated. General defects with individual depth not exceeding half of the allowable deviation may not be repaired if they do not affect the use.
3 Test methods
GB/T14990-94
The test methods and sampling values ​​for various quality inspections of alloy bars shall comply with the provisions of Table 4. 4
4 Inspection rules
4.1 Inspection and acceptance
Inspection items
Chemical analysis
Magnetic properties
Surface quality
Test methods
YＲ 789-75
YB35-78
Impact method or loop instrument method
Use a tool that can ensure accuracy
The inspection and acceptance of alloy bars shall be carried out by the supplier's technical supervision department. 4.2 Batch rules
Sampling position
GB222-63
Any part of the finished product
1 piece per workshop
2 pieces per furnace
Alloy bars should be submitted for inspection and acceptance in batches. Each batch should consist of bars with the same alloy grade, the same smelting furnace number, the same cross-sectional size and the same processing method.
4.8 Sampling quantity
The sampling quantity for the basic inspection of alloy bars should be in accordance with the provisions of Table 4. 4.4 Re-inspection and judgment rules
When the hysteresis performance test results of alloy bars are unqualified, two samples are allowed to be re-tested. If the re-inspection results are still unqualified, the batch of alloys will not be accepted, but the supplier can change the heat treatment system and re-submit it for inspection as a new batch. 5 Packaging, marking and quality certificate
The packaging, marking and quality certificate of alloy bars shall comply with the requirements of YI/T5242-93 "General provisions for packaging, marking, marking and quality certificate of precision alloys".
A.1 Sample preparation
GB/T 1499094
Appendix A
Preparation of magnetic test samples of hysteresis alloys and test and calculation methods of hysteresis parameters
(Supplement)
A.1.1 The sample is made into a bar shape, the outer diameter of the bar is 40mm and the inner diameter is 32mm. Other annular sizes with a ratio of the semi-mean diameter to the radial width greater than or equal to T-8 can also be used. The thickness of the bar is 1 to 5mm. For the two grades of alloys 2125 and 2127, it is allowed to use sample specimens for inspection, but the length ratio of the sample should be equal to or equal to T-5. The two ends of the bar specimen should be parallel to each other and perpendicular to the F axis. The cross-sectional area of ​​the sample should be kept consistent along the entire length, and the difference should not exceed 1% of its minimum cross-sectional area. A.1.2 After heat treatment, the sample should be descaled. A.2 Testing and calculation methods of hysteresis parameters
A,2.1 The cross-sectional area S, of the annular sample is recommended to be calculated using the following formula; Sa-
-cross-sectional area of ​​the sample, cm\,
Formula 41: S,-—
W weight of the sample, g:
average diameter of the sample, cmz
-alloy density, g/cm\.
If the above method is not used, the sample size can be measured with a precision dry ruler to calculate the surface area. A,2.2 The sample, measuring winding and magnetizing winding must be insulated. The measuring winding is wound on the inner layer. A.2.3 During the test, the Hu value is first determined, and then the hysteresis loop is made under this magnetic field to obtain other hysteresis parameters. A.2.4 Parameters of the galvanneal tape are calculated as follows: Pu = SKH KR
Where: S - measured magnetic tape loop product, cm; Pu - specific hysteresis loss corresponding to the maximum permeability point, erg/cm\; Ku - coefficient of hysteresis corresponding to the maximum permeability point; Hμ - magnetic field intensity corresponding to the maximum permeability point, e; Bu - magnetic induction intensity corresponding to the maximum permeability point, Gs! KH
- magnetic field intensity coordinate calibration coefficient:
magnetic induction intensity coordinate calibration coefficient.
+ (A1)
. (A3)
GB/T 14990-94
Appendix B
Heat treatment system of alloy specimens
(reference)
Heat treatment system of alloy specimens is recommended to be determined by the table. Table R
Gold medal
Heating temperature, C
(under protective steam)
1200110
1200 ± 10
[250 ±10
1250±10
Housing time
15 ~ 30
Fire temperature
625~700
625-700
625~725
625~725
Housing time
60-120
Cooling method
Other properties of the alloy are listed in Table C.
Alloy grade
Additional remarks:
Specific gravity (d)
G.T1499094
Appendix C
Other properties of alloy
(reference)
Expansion coefficient (α)
(20~300℃）
11.24 × 10- 6
11,10 × 10-6
11.18x 10
11.21×10-6
This standard is 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 is Liu Yushu.
Resistivity (p)
(Zaiwen)
35 ~42
Elastic modulus (E)
kg/mm2
210-00
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.