GB/T 3082-2020Galvanized or zinc-aluminum alloy-coated low-carbon steel wire for armoured cables (English PDF)

3.1 Type of coating

The coating categories are divided into three categories. the first category is pure zinc coating; the second category is zinc-5% aluminum alloy coating; the third category is zinc-10% aluminum alloy coating. The coating type should be indicated in the contract.

3.2 Plating group

The steel wire coating is divided into two groups according to weight. group I and group II.

3.3 Mark

The marking of the steel wire consists of the coating category, the nominal diameter of the steel wire, the coating group and the number of this standard. Specific examples are as follows.

Example 1.Galvanized steel wire for group I armored cables with a nominal diameter of 4.0mm is marked as.

Example 2.Galvanized -5% aluminum alloy coated steel wire for group I armored cable with a nominal diameter of 2.5mm is marked as.

Example 3.Galvanized-10% aluminum-alloy coated steel wire for group I armored cable with a nominal diameter of 2.7mm is marked as.

5.1 Nominal diameter and allowable deviation

The nominal diameter and allowable deviation of the steel wire should meet the requirements of Table 1. If the supply and demand parties have agreed otherwise, the agreement shall be implemented.

5.2 Length and allowable deviation

The length of the steel wire is determined according to the requirements of the buyer, and the allowable deviation is 0%~2% of the length. If there is another agreement between the supplier and the demander, the agreement shall be implemented.

5.3 Out-of-roundness

The out-of-roundness of the steel wire should not be more than half of the diameter tolerance.

5.4 Weight

The steel wire is delivered according to actual weight.

7.2 Wire diameter

The diameter of the steel wire should be measured once in the direction of 90° with each other on the same cross section, and the average value of the two measurements shall be taken as the diameter of the steel wire.

7.3 Out-of-roundness

Wire out-of-roundness is the difference between the largest diameter and the smallest diameter on the same cross-section.

7.4 Winding test

The steel wire is tightly wound on the mandrel specified in Table 2 at a speed not exceeding 15r/min.

7.5 Coating adhesion test

The steel wire is tightly wound on the mandrel specified in Table 3 at a speed not exceeding 15r/min.

7.6 Numerical rounding

The rounding and judgment of the steel wire inspection and the measured value of the inspection shall be carried out according to YB/T 081.

8.1 Inspection and acceptance

The steel wire is inspected by the supplier's quality supervision department. The purchaser has the right to carry out acceptance inspection in accordance with the provisions of this standard.

8.2 Batching rules

Unless otherwise agreed by the supplier and the demander, the steel wire shall be checked and accepted in batches. Each batch shall be composed of steel wires of the same coating category, the same coating group, and the same diameter.

8.3 Re-inspection and judgment

The re-inspection and judgment rules of steel wire shall be carried out in accordance with the provisions of GB/T 2103.

A.1 Principle

Add an excess of EDTA standard solution to the slightly acidic solution to form complexes with iron, zinc, copper and other elements, and then store it in acetic acid.

At the bottom, boil all aluminum to form complexes. Using xylenol orange as an indicator, use lead nitrate standard solution to drip back excess EDTA. Join The fluoride demasks Al-EDTA and releases the same amount of EDTA as aluminum, which is then titrated with lead nitrate standard titration solution to calculate the aluminum content.

A.2 Reagents

A.2.1 Potassium fluoride (KF·2H2O)

A.2.2 Decoating hydrochloric acid corrosion inhibitor. HCl (11) and hexamethylenetetramine (3%) are mixed in equal volume.

A.2.3 Hydrochloric acid (1 1).

A.2.4 Ammonia (1 1).

A.2.5 Ammonium acetate solution (50%)

A.2.6 Acetic acid-sodium acetate buffer solution (pH=5.5). Weigh.200g of sodium acetate (containing 3 crystal water), dissolve in water, and add 9mL of ice Acetic acid, then diluted with water to 1000mL.

A.2.7 EDTA standard solution, c(EDTA)=0.05mol/L. Weigh 19g EDTA (containing 2 crystal water) in a 500mL beaker After dissolving in water, transfer to a 1000mL volumetric flask and dilute to the mark with water.

A.2.8 Lead nitrate standard titration solution, c[Pb(NO3)2]=0.025mol/L. Weigh 8.3g lead nitrate, dissolve it in water, and move it to Dilute to the mark in a 1000mL volumetric flask and calibrate.

A.2.9 Congo red test paper.

A.2.10 Xylenol orange indicator (0.25%).

A.3 Analysis steps

A.3.1 Sample preparation

According to formula (A.1) calculation results (retained integer, unit. cm) cut the total length of the sample, the detection needs can be divided into several small sections.

A.3.2 Test process

Wipe the surface of the sample with gasoline and dry it, then wipe it with absolute ethanol and dry it, put it in an oven and bake it at 105°C for 30 minutes, and then dry it.

Cool in the device for 30 minutes, weigh it to obtain m1, then put it in 100mL de-plating solution (A.2.2) to remove the coating, then wash the sample with distilled water, and then