GB/T 24202-2021Carbon steel wire for tension members of optical fiber cable (English PDF)

Foreword

This document was drafted in accordance with the rules provided in GB/T 1.1-2020 Directives for Standardization - Part 1: Rules for the Structure and Drafting of Standardizing Documents.

This document serves as a replacement for GB/T 24202-2009 Carbon Steel Wire for Optical Fiber Cable Tension Members. In comparison with GB/T 24202-2009, apart from editorial modifications, the main technical changes are as follows:

a) Classification and labeling are added (see Chapter 4);

b) Zinc layer grade of galvanized steel wire is added to the ordering content (see Chapter

5);

c) The nominal diameter of steel wire is expanded to 0.35 mm ~ 3.0 mm (see 6.1; 6.2 of Version 2009);

d) The term straightness is deleted, the inspection methods for ring diameter and warp height are clarified, and the indicator requirements for free ring diameter are enhanced (see 6.3; 5.2 of Version 2009);

e) The provisions on wire rods are modified (see 7.1.1; 6.1 of Version 2009);

f) The provisions on zinc ingots for galvanizing are added (see 7.1.2);

g) The scope of application of tensile strength grade is modified (see 7.2.1; 6.2 of Version

2009);

h) The provisions on the technical indicators of 0.35 mm <= d < 0.50 mm steel wires are added (see Chapter 7);

i) The 2,550 strength and corresponding torsion and repeated bending indicators are added (see 7.3 and 7.4);

j) The provisions on knotting and stretching are added (see 7.5);

k) The provisions on the indicator and test method of modulus of elasticity are modified (see 7.6 and 8.4; 6.5 and 7.5 of Version 2009);

l) "Residual ductility" is modified into "residual elongation" (see 7.7; 6.6 of Version

2009);

1 Scope

This document specifies the terms and definitions, classification and labeling, ordering content, dimensions, shape and allowable deviations, technical requirements, inspection methods, inspection rules, packaging, marking, transportation, storage, quality assurance period and quality certificate of carbon steel wire for tension members of optical fiber cable.

This document is applicable to galvanized and phosphated round carbon steel wire for tension members of optical fiber cable (hereinafter referred to as the steel wire). Steel wires for tension members of cables with other purposes may take this as a reference.

2 Normative References

The content of the following documents constitutes indispensable clauses of this document through normative references in the text. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this document.

GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature

GB/T 238 Metallic Materials - Wire - Reverse Bend Test

GB/T 239.1 Metallic Materials - Wire - Part 1: Simple Torsion Test

GB/T 470-2008 Zinc Ingots

GB/T 1839 Test Method for Gravimetric Determination of the Mass Per Unit Area of Galvanized Coatings on Steel Products

GB/T 2103 General Requirements for Acceptance, Packing, Marking and Quality Certification of Steel Wire

GB/T 2976 Metallic Materials - Wire - Wrapping Test

GB/T 4354 Hot Rolled Quality Carbon Steel Wire Rods

GB/T 9792 Conversion Coatings on Metallic Materials - Determination of Coating Mass Per Unit Area - Gravimetric Methods

GB/T 22315 Metallic Materials - Determination of Modulus of Elasticity and Poisson's Ratio

GB/T 24242.2 Non-alloy Steel Wire Rods for Conversion to Wire - Part 2: Specific Requirements for General Purpose Wire Rod

YB/T 081 Rule for Rounding off of Numerical Values and Judgement of Testing Values for Technical Standards of Metallurgy

3 Terms and Definitions

The following terms and definitions are applicable to this Standard.

4 Classification and Labeling

4.1 The steel wire is classified into seven strength grades in accordance with the nominal tensile strength (unit: MPa): 1370, 1570, 1770, 1960, 2160, 2350 and 2550.

4.2 In accordance with the surface conditions, the steel wire is classified into two categories: phosphate and galvanized. Galvanized steel wire is classified into three grades: AB, C and E in accordance with its galvanizing weight.

4.3 Examples of labeling are as follows: EXAMPLE 1:

Carbon steel wire for tension members of optical fiber cable with a nominal diameter of 1.40 mm, a strength grade of 1960 and surface phosphating is labeled as:

Phosphated steel wire for optical fiber cable 1.40-1960-GB/T 24202-2021 EXAMPLE 2:

Carbon steel wire for tension members of optical fiber cable with a nominal diameter of 1.60 mm, a strength grade of 1570 and surface plated with E-grade zinc layer is labeled as: Galvanized steel wire for optical fiber cable 1.60-1570-E-GB/T 24202-2021

5 Ordering Content

An ordering contract that complies with this document shall include the following main contents:

a) Serial No. of this document;

9 Inspection Rules

10 Packaging, Marking, Transportation, Storage, Quality

Assurance Period and Quality Certificate