JB/T 1373-1974 Technical requirements for electrical contacts JB/T1373-1974 Standard download decompression password: www.bzxz.net

The standard of the People's Republic of China for the pressure machinery industry is JB/T13731974
1974-07-01
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JB/T13731974
This standard applies to contact products of copper tungsten, silver tungsten, silver nickel, silver iron, silver oxide, silver stone, copper graphite and other series and varieties manufactured by powder metallurgy, as well as silver cadmium oxide products produced by internal oxidation.
The above-mentioned electrical contact products are mainly used in high and low voltage electrical appliances, and some are also used as electrode materials. I. Technical requirements
1. The basic shape and allowable tolerance of electrical contact products (hereinafter referred to as tolerance): (1) See Figure 1 for cylindrical plane contacts and cylindrical spherical contacts. Figure 1
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1974-07-01
JB/T13731974
Nominal size
JB/T13731974
(2) See Figure 2 for rectangular plane contacts and rectangular cylindrical contacts; H
Nominal size
Nominal size
Nominal size
Nominal size
JB/T13731974
Nominal size
|Nominal size
(3) See Figure 3 for cylindrical flat riveted contacts and cylindrical spherical riveted contacts, H
Continued Table 2
JB/T13731974
Nominal size
(4) The radius R of the spherical and cylindrical surfaces and other shapes and the tolerances of contact products exceeding the dimensions in Table 1, Table 2 and Table 3 shall be as follows: Less than or equal to 3 mm
More than 3 to 6 mm
More than 6 to 10 mm
More than 10 to 30 mm
More than 30 to 50 mm
More than 50
The tolerance for thickness shall be twice the negative tolerance of the above corresponding dimensions. 2. The composition and performance of electrical contact products shall comply with the requirements of Table 4, tolerance ±0.10 mm,
tolerance ±0.12 mm;
tolerance ±0.15 mm
tolerance ±0.20 mm
tolerance ±0.25 mm
tolerance ±0.30 mm;
silver oxide pick 12
silver oxide 15
silver nickel 30
silver iron 7||tt| |Silver graphite 5
Copper graphite 5
Silver tungsten 30
Silver tungsten 40
Ag—Ni30
Ag—Fe7
Cu—C5
JB/T13731974
Chemical composition
Ag—W30
Ag-W40
Ag-W70
Silver tungsten 70
95 ±1
30 ±1
Hardness (HB)
(not less than)
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(not less than)
Resistivity
microohm·cm
(not more than)
Flexural strength
kg/mm2
(not less than)
Copper tungsten 50
Copper tungsten 60
Copper Tungsten 70
Copper Tungsten 80
Cu-W50
Cu-W60
Cu-W70
Cu-W80
JB/T13731974
Chemical Composition
Hardness (HB)
(not less than)
Note, ④ Elements added to improve performance are not impurities. Hard
g/cm3
(not less than)
Resistivity
microohm·cm
(not greater than)
Continued Table 4
Bending Strength
kg/mm*
(not less than)
③Hardness Value "Hard" means that the contact product is not heat treated after pressure processing. "Soft state" means the hardness value of the contact product after
impregnation sintering or pressure processing and annealing. 3. The finish of the working surface of the electrical contact product should not be less than √4. 4. The electrical contact product must be free of cracks, bubbles, and no significant dents, missing edges, missing corners and other defects on the surface. Its cross-sectional structure should be dense, without stratification or sandwiching. 5. The microstructure (particles or grains) of the electrical contact product should be evenly distributed. 6. The welding surface of the silver oxide electrical contact product should have a uniform silver layer, and the welding surface should be marked. 7. Silver oxide, silver nickel, silver iron, silver graphite, copper graphite and silver tungsten contact products should have considerable thermal stability. Silver oxide is heated at 1000°C±10, silver nickel is heated at 1020°C±10, silver iron is heated at 970°C±10, silver graphite is heated at 930°C±10, copper graphite is heated at 1020°C±10, and silver tungsten is heated at 970°C±10 for 1 minute. The contact does not deform, and there is no large fusible component overflowing from the surface, and there are no cracks or pores. Copper tungsten contact products are not subject to thermal stability tests.
JB/T13731974
II. Test methods and acceptance rules
8. The appearance of the electrical contact in Article 4 of this standard shall be observed with the naked eye. 9. The surface cracks and cross-sections of the electrical contact in Article 4 of this standard shall be observed with a magnifying glass of not less than 15 times. 10. The dimensions of the electrical contact products are checked with a vernier caliper or an outside micrometer. 11 Density is measured on an analytical balance according to the Archimedean principle. The measurement method is shown in JB1374-74 "Methods for measuring basic properties of electrical contacts". 12. Resistivity is measured in JB1374-74 "Methods for measuring basic properties of electrical contacts". 13. Hardness is measured with a Brinell hardness tester. The measurement method is shown in JB1374-74 "Methods for measuring basic properties of electrical contacts".
14. Bending strength is measured on a mechanical properties testing machine. The support span for bending is 30 mm. The cross-section of the test sample is rectangular, with dimensions of 50 mm in length, 10 mm in width, and 4 mm in thickness. The measurement method is shown in JB1374-74 "Methods for measuring basic properties of electrical contacts". 15. Microstructure is observed with a metallographic microscope on the polished surface of the cross section. 16. The component analysis of electrical contact products adopts the element quantitative analysis method of each component. If there is a silver layer on the welding surface before sampling, it must be removed. 17. The thermal stability test samples of electrical contact products adopt the samples after the bending strength test, and are carried out in a muffle furnace without protective atmosphere. When the furnace temperature reaches the test temperature, the sample is put into the furnace and taken out after 1 minute. 18. The quality inspection of electrical contact products is carried out in batches by the factory technical inspection department. Each batch should have the same ingredients and the same process.
19. The quality inspection of electrical contact products is carried out according to the following sampling: (1) Appearance inspection 100% per batch,
(2) Dimension inspection 10% per batch,
(3) Density inspection no less than 3 per batch, (4) Hardness inspection no less than 3 per batch
(5) Resistivity inspection no less than 3 per batch, (6) Bending strength inspection no less than 3 per batch, () Microstructure, chemical composition analysis and thermal stability test are inspected regularly. 20 Regular inspection items, when raw materials, processes and equipment are unchanged, must be inspected at least once a quarter.
21 When raw materials, processes and equipment are changed, all basic performance inspections must be carried out. 22. Dimension inspection, if the size does not meet the requirements, it is allowed to re-inspect with double the number. If there are still more than (including
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