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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 20492-2006 Zinc-5% aluminum-mixed mischmetal alloy-coated steel wire and steel wire strand. the following main technical changes have been made with respect to GB/T 20492-2006:
——The mechanical properties of zinc-coated steel wire of all levels of strength are deleted from class C coating of steel wire (see Table 4 to Table 8 hereof; Table 4 of 2006 edition);
——The weight of class C coating of the steel wire is deleted (see Table 2 hereof; Table 5 of 2006 edition);
——The weight of class D coating of the steel wire for steel wire strand is deleted (see Table 16 hereof; Table 13 of 2006 edition);
——The requirement for the test method for minimum breaking force of steel wire strand is added, that is, calculate the minimum breaking force of steel wire strand by testing the total breaking force of split steel wire in the steel wire strand (see 15.10 hereof);
——The zinc-coated steel wires of class 4 and class 5 strength are added, and their performance parameters are specified in detail (see Table 7 and Table 8 hereof);
——The mandrel diameter of winding test for zinc-coated steel wire of class 3 strength with nominal diameter ranging from 2.75 mm to 5.50 mm is modified from 5D to 4D (see Table 6 hereof; Table 4 of 2006 edition);
——The code of strength in the "Representation method for models of zinc-coated steel wires for overhead stranded wires" is modified to be expressed by "class 1, class 2, class 3, class 4 and class 5" (see Table 4 to Table 8 hereof; Table 4 of 2006 edition);
——The ordering information, test methods, packaging, marking and quality certificate are specified in detail according to China's national conditions (see clauses 4, 8, 11, 15 and 18 hereof).
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous edition of this standard is as follow:
——GB/T 20492-2006.
Zinc-5% aluminum-mixed mischmetal alloy-coated steel wire and steel wire strand
1 Scope
This standard specifies the classification, ordering information, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of zinc-5% aluminum-mixed mischmetal alloy-coated steel wire (hereinafter referred to as steel wire) and steel wire strand (hereinafter referred to as steel wire strand).
This standard is applicable to the manufacture of steel wires for overhead stranded wires, and also applicable to steel wire strands used for overhead power ground wire, communication cable, hanger or hanging, tying and fixing objects. These alloy-coated products are suitable for workplaces requiring corrosion resistance and tensile strength.
Note: The technical indicators of steel wire are specified in clause 3 to clause 9 of this standard, and that of steel wire strand are specified in clause 10 to clause 16.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 228.1 Metallic materials—Tensile testing—Part 1: Method of test at room temperature
GB/T 239.1 Metallic materials—Wire—Part 1: Simple torsion test
GB/T 701 Hot rolled low carbon steel wire rods
GB/T 1839 Test method for gravimetric determination of the mass per unit area of galvanized coatings on steel products
GB/T 2103 General provisions for checking, packing, marking and quality certification of steel wire
GB/T 2104 Steel wire ropes—Packing, marking and certificate—General requirements
GB/T 2972 Test method for uniformity of zinc coating on zinc-coated steel wire by the copper sulphate dip
GB/T 2976 Metallic materials—Wire—Wrapping test
GB/T 4354 Hot rolled quality carbon steel wire rods
GB/T 8358 Steel wire ropes—Determination of measured breaking force
GB/T 21839 Test methods of steel for prestressing concrete
GB/T 24242.2 Non-alloy steel wire rod for conversion to wire—Part 2: Specific requirements for general purpose wire rod
YB/T 081 Rule for rounding off of numberical values and judgment of testing values for technical standards of metallurgy
YB/T 5357 Non-ferrous metallic coatings on steel wire—Zinc or zinc-5% aluminum alloy coating
YS/T 310 Zinc alloy ingot for hot dip galvanizing
3 Classification of steel wire
3.1 Grading of coating weight
The steel wires are classified by coating weight into class A and class B.
3.2 Grading of tensile strength
The steel wires are classified by nominal tensile strength into grade 1 strength, grade 2 strength, grade 3 strength, grade 4 strength and grade 5 strength.
4 Ordering information of steel wire
The contract for ordering according to the standard shall include the following main information:
a) Serial number of this standard;
b) Product name;
c) Nominal diameter;
d) Nominal tensile strength grade;
e) Coating weight class;
f) Quantity (length);
g) Usage;
h) Other requirements.
5 Size, shape and weight of steel wire
5.1 Size and permissible deviation of steel wire
5.1.1 The nominal diameter and permissible deviation of steel wires shall meet those specified in Table 1. If the supplier and the purchaser agree otherwise, the agreement shall prevail.
Table 1 Nominal diameter and permissible deviation of steel wire
Dimensions in millimeters
5.1.2 The length of steel wire shall be determined according to the requirements of the purchaser, and the permissible deviation shall be 0% to +2% of the length. If the supplier and the purchaser agree otherwise, the agreement shall prevail.
5.2 Weight of steel wire
The steel wire shall be delivered according to actual weight.
6 Example of steel wire designation
The example of steel wire designation is as follows:
7 Technical requirements for steel wire
7.1 Material
7.1.1 Wire rods for steel wires shall comply with GB/T 4354 or GB/T 24242.2, and the steel grade shall be selected by the steel wire supplier. Other steel grades of wire rods may also be selected according to the agreement between the supplier and the purchaser.
7.1.2 The chemical composition of zinc-5% aluminum-mixed mischmetal alloy ingot for hot-dip coating shall comply with YS/T 310. According to the agreement between the supplier and the purchaser, the range of aluminum content may also be adjusted appropriately.
7.2 Joint
7.2.1 Resistance butt welding joint or flash welding joint may be used in any working procedure before final cold drawing, but the steel wire before coating shall not be welded any more after final cold drawing.
7.2.2 Welding equipment and process shall ensure that the ultimate tensile strength of finished steel wire samples with welded parts is not less than 96% of the specified minimum stress at 1% elongation. The welded parts are not required to meet the requirements of stress and elongation at 1% elongation, and no winding test is required.
Foreword i
1 Scope
2 Normative references
3 Classification of steel wire
4 Ordering information of steel wire
5 Size, shape and weight of steel wire
6 Example of steel wire designation
7 Technical requirements for steel wire
8 Test items and methods of steel wire
9 Inspection rules of steel wire
10 Classification of steel wire strand
11 Ordering information of steel wire strand
12 Size and shape of steel wire strand
13 Example of steel wire strand designation
14 Technical requirements of steel wire strand
15 Test items and methods of steel wire strand
16 Inspection rules for steel wire strand
17 Rounding off for numerical values
18 Packaging, marking and quality certificate
Annex A (Normative) Determination of aluminum content in steel wire coating
