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This standard is drafted according to the rules specified in GB/T 1.1-2009.
This standard replaces GB/T 3952-2008 Copper Drawing Stock for Electrical Purpose, and the following technical changes have been made with respect to GB/T 3952-2008 (the previous edition):
——In Normative References, GB/T 238 Metallic Materials - Wire - Reverse Bend Test is deleted while YS/T 464 Methods for Nalytical of Copper Cathode - The Optical Emission Spectrometry and GB/T 23606 Copper-Hydrogen Embrittlement Test Method are added.
——The requirements for the content of impurity element Bi in designations T2 and TU2 are adjusted, with the mass fraction changed from 0.0006% to 0.000 5%.
——The total content of impurities in designation T3 is changed from 0.05% to 0.06%.
——The statement that the gauge length of the specimen for elongation test is 200mm is made clear.
——The gauge length of the specimen for copper powder quantity and torsion off tests is unified as 250mm.
——Index requirements for the surface oxide film of copper drawing stock are added, and the determination method of oxide film is added as Annex C.
——Sampling quantity for chemical composition, electrical performance, copper powder quantity and hydrogen embrittlement tests are changed from per 15 coils or 30t to per 15 coils or 60t.
——The hydrogen embrittlement test method for oxygen-free copper drawing stock is adjusted, with Annex B Hydrogen Embrittlement Test Method for Oxygen-free Copper Drawing Stock changed to GB/T 23606 Copper - Hydrogen Embrittlement Test Method.
This standard was proposed by the China Nonferrous Metals Industry Association.
This standard is under the jurisdiction of SAC/TC 243 National Technical Committee on Nonferrous Metals of Standardization Administration of China.
The previous editions of the standard replaced by this standard are as follows:
——GB/T 3952.1-1989, GB/T 3952.2-1989, GB/T 3952.3-1989, GB/T 3952-1998, GB/T 3952-2008.
——GB/T 3954.1-1989.
Copper Drawing Stock for Electrical Purpose
1 Scope
This standard specifies requirements, test methods, inspection rules, marking, packaging, transport, storage, quality certificate and purchase order (or contract) content of copper drawing stock for electrical purpose.
This standard is applicable to circular cross sectional copper drawing stock, in diameter from 6.0 mm to 35.0 mm, of copper conductors for further drawing wire or other electrical purpose.
2 Normative References
The following documents for the application of this document are essential. For dated reference, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 230.1 Metallic Materials - Rockwell Hardness Test - Part 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T)
GB/T 3048.2 Test Methods for Electrical Properties of Electric Cables and Wires - Part 2: Test of Electrical Resistivity of Metallic Materials
GB/T 4909.2 Test Methods for Bare Wires - Part 2: Measurement of Dimensions
GB/T 4909.3 Test Methods for Bare Wires - Part 3: Tensile Test
GB/T 4909.4 Test Methods for Bare Wires - Part 4: Torsion Test
GB/T 5121 (All Parts) Methods for Chemical Analysis of Copper and Copper Alloys
GB/T 23606 Copper-Hydrogen Embrittlement Test Method
YS/T 464 Methods for Analytical of Copper Cathode - the Optical Emission Spectrometry
3 Requirements
3.1 Product classification
3.1.1 Designation, condition and specification
The designation, condition and specification of copper drawing stock shall be in accordance with those specified in Table 1.
Table 1 Designation, Condition and Specification
Designation Condition Diameter /mm
T1, T2, T3 Hot-rolled (M20) 6.0~35.0
TU1, TU2 As-cast(M07)
As-drawn (hard)(H80) 6.0~12.0
3.1.2 Marking example
Marking examples expressed according to the sequence of designation, state, diameter and standard number are as follows:
Example 1: Hot-rolled (M20) copper drawing stock with designation of T1 and diameter of 8.0mm is marked as:
Copper drawing stock T1 M20 φ8.0 GB/T 3952-2016
Example 2: As-drawn (hard) (H80) copper drawing stock with designation of TU2 and diameter of 10.0 mm is marked as:
Copper drawing stock TU2 H80 φ10.0 GB/T 3952-2016
3.2 Chemical composition
3.2.1 The chemical composition of copper drawing stock with designation of T1 and TU1 shall comply with those specified in Table 2, with the oxygen contents of T1 and TU1 no greater than 0.040% and 0.0010% respectively.
Table 2 Chemical Composition of Copper Drawing Stock with Designation of T1 and TU1
Element group Impurity elements Mass fraction /%, ≤ Total mass fraction of element group /%, ≤
1 Se 0.000 2 0.000 30 0.000 3
Te 0.000 2
Bi 0.000 2 —
2 Cr — 0.001 5
Mn —
Sb 0.000 4
Cd —
As 0.000 5
P —
3 Pb 0.000 5 0.000 5
4 S 0.001 5 0.001 5
5 Sn — 0.002 0
Ni —
Fe 0.001 0
Si —
Zn —
Co —
6 Ag 0.002 5 0.002 5
Total content of impurities, mass fraction/%, ≤ 0.006 5
Note: the total content of impurities is the sum of actual measured values of all impurity elements listed in this Table.
3.2.2 The chemical composition of copper drawing stock with designation of T2 and TU2 shall comply with those specified in Table 3, with the oxygen contents of T2 and TU2 no greater than 0.045% and 0.002 0% respectively.
Table 3 Chemical Composition of Copper Drawing Stock with Designation of T2 and TU2
Mass fraction /%
Cu+Ag Impurity element ≤
≥ As Sb Bi Fe Pb Sn Ni Zn S P
99.95 0.001 5 0.001 5 0.000 5 0.002 5 0.002 0.001 0 0.002 0 0.002 0.002 5 0.001
Note: the Cu+Ag contents in this table are directly measured values.
3.2.3 The chemical composition of copper drawing stock with designation of T3 shall comply with those specified in Table 4, with the oxygen contents of T3 no greater than 0.05%.
Table 4 Chemical Composition of Copper Drawing Stock with Designation of T3
Mass fraction /%
Cu+Ag Impurity element, ≤
≥ As Sb Bi Fe Pb Sn Ni Zn S P Cd Mn Impurity sum
99.90 — — 0.002 5 — 0.005 — — — — — — — 0.06
Note:
1 The total content of impurities is the sum of actual measured values of all impurity elements listed in this Table.
2 The Cu+Ag contents in this table are directly measured values.
3.3 Dimension and its permissible deviation
3.3.1 For copper drawing stock, the diameter and its permissible deviation shall be in accordance with those specified in Table 5.
Table 5 Diameter and Its Permissible Deviation In: mm
Nominal diameter 6.0~6.35 >6.35~12.0 >12.0~19.0 >19.0~25.0 >25.0~35.0
Permissible deviation +0.5
-0.25 ±0.4 ±0.5 ±0.6 ±0.8
3.3.2 Copper drawing stock shall be supplied in coils constituted by only one continuous piece of copper drawing stock, and no welding is allowed. The minimum coil weight shall not be inferior to 1t, and the delivery weight may be determined through negotiation by both parties.
3.4 Surface quality
3.4.1 Copper drawing stock shall be round and smooth with uniform dimension (in accordance with the requirements of 3.3.1), and can be directly used without acid-washing and scaling.
3.4.2 The surface of copper drawing stock shall be free from frilling, flash edge, cracks, impurity and other defects which may influence its application.
3.4.3 The surface quality of the copper drawing stock used for enameled wire shall be subjected to negotiation between both parties and indicated in the contract; the thickness of oxide film shall not be greater than 75nm.
3.5 Mechanical property
Mechanical properties of copper drawing stock shall meet those specified in Table 6; after being annealed sufficiently, the copper drawing stock in H80 condition shall be able to meet the elongation requirements of products (in M07 condition) with corresponding designations specified in Table 6.
Table 6 Tensile Strength and Elongation
Designation Condition Diameter /mm Tensile strength /MPa
≥ Elongation /%
≥
T1 Hot-rolled (M20) 6.0~35 40
T2 37
T3 35
TU1 As-cast (M07) 40
TU2 37
TU1 and TU2 As-drawn (hard)
(H80) 6.0~7.0 370 2.0
>7.0~8.0 345 2.2
TU1 and TU2 As-drawn (hard)
(H80) >8.0~9.0 335 2.4
>9.0~10.0 325 2.8
>10.0~11.0 315 3.2
>11.0~12.0 290 3.6
3.6 Torsional property
Copper drawing stock (in M20 and M07 condition) with diameter of 6.0mm~10.0mm shall be subjected to torsion test, and torsional property of copper drawing stock with different designations shall meet the requirements specified in Table 7.
Table 7 Torsional Property of Copper Drawing Stock
Designation Condition Number of turns at positive rotation Number of turns at reverse rotation to fracture, ≥
T1 Hot-rolled (M20) 25 25
T2 25 20
T3 25 17
TU1 As-cast(M07) 25 25
TU2 25 20
3.7 Electrical property
3.7.1 For copper drawing stock specimen prepared in accordance with the requirements of 4.6.3, the resistivity of copper drawing stock shall be in accordance with those specified in Table 8.
3.7.2 The resistivity of copper drawing stock specimen prepared in accordance with the requirements of 4.6.2 shall be in accordance with those specified in Table 8 for copper drawing stock (in M (M07 or M20) conditions) with corresponding designations.
Table 8 Resistivity
Designation Condition Mass resistivity ρ20°
Ω·g/m2, ≤ Volume resistivity ρ20°
Ω·mm2/m, ≤
T1 Hot-rolled (M20) 0.151 76 0.017 070
T2 and T3 0.153 28 0.017 241
TU1 As-cast (M07) 0.151 76 0.017 070
TU2 0.153 28 0.017 241
TU1 As-drawn (hard)(H80) 0.155 61 0.017 504
TU2 0.157 98 0.017 774
3.8 Other requirements for copper drawing stock
3.8.1 Copper powder quantity
For copper drawing stock manufactured by continuous casting and rolling, copper powder quantity determination shall be carried out according to the methods specified in Annex A (only applicable to copper drawing stock with φ8mm) if it is required by the user and indicated in the contract. Copper powder quantity of copper drawing stock for enameled wire purpose shall not be greater than 8mg/250mm and that for copper drawing stock for other purposes shall not be greater than 15mg/250mm.
3.8.2 Hydrogen embrittlement
For copper drawing stock with designation of TU1 and TU2, which are used in the field with special requirements (with strict restriction for oxygen content), such as irregular electric wires and cables as well as magnetic wires, hydrogen embrittlement test shall be carried out if it is required by the user and indicated in the contract. Hydrogen embrittlement test shall be carried out according to the methods specified in GB/T 23606; products with designation TU1 shall be able to withstand at least 10 times of alternating bending without fracture, while products with designation TU2 shall be able to withstand at least 8 times of alternating bending without fracture.
3.8.3 Annealing property
If the user has certain requirements on the annealing property of copper drawing stock with designation T3 and such requirements are indicated in the contract, the annealability test may be carried out according to the method specified in Annex B, and the annealing property of this batch of products shall be indicated in the supply quality certificate. [If measured Rockwell Hardness (Grade F) is less than 60HRF, the product shall be regarded as being completely annealed; if it is in the range of 60HRF to 70HRF, the product is regarded as being moderately annealed; and if it is above 70HRF, the product is regarded as being low annealed.]
Foreword i
1 Scope
2 Normative References
3 Requirements
4 Test Methods
5 Inspection Rule
6 Marking, Packaging, Transport, Storage and Quality Certificate
7 Content of Purchase Order (or Contract)
Annex A (Informative) Copper Drawing Stock for Electrical Purpose - Determination of Copper Powder Quantity - Dry Brushing Method
Annex B (Informative) Annealability Test Methods for Copper Drawing Stock
Annex C (Informative) Oxide Film Test Methods for Copper Drawing Stock