GB/T 2972-2016 English PDF (GBT2972-2016)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get Quotation: Click GB/T 2972-2016 (Self-service in 1-minute)
Historical versions (Master-website): GB/T 2972-2016
Preview True-PDF (Reload/Scroll-down if blank)

GB/T 2972-2016: Test method for uniformity of zinc coating on zinc-coated steel wire by the copper sulphate dip
GB/T 2972-2016
Test method for uniformity of zinc coating on zinc-coated steel wire by the copper sulphate dip
ICS 25.220.40
H25
National Standards of People's Republic of China
Replace GB/T 2972-1991
Test method for copper sulfate of galvanized steel wire
Lt;/RTI and
Coatingsonsteelwire-Part 2. Zincorzinc-aloycoating, NEQ)
2016-06-14 release
2017-05-01 Implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People 's Republic of China
China National Standardization Management Committee released
Preface
This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard instead of GB/T 2972-1991 "galvanized steel wire zinc sulfate test method", compared with GB/T 2972-1991, the main
The changes are as follows.
--- The scope of application of zinc-aluminum alloy coating steel wire can refer to this standard;
--- increase the normative reference file;
--- modified the sample preparation requirements, the sample length is modified to about 250mm;
--- modified the reagent preparation requirements, copper sulfate crystals to analysis of pure, the amount changed to 314g/L, the temperature changed to 20 ℃ ± 2 ℃, and dissolved
The process of not heating;
- the removal of copper hydroxide and copper carbonate in neutralizing reagents;
--- the proportion of the test solution to remove the requirements;
- Added method for the determination of zinc content in the Appendix A copper sulfate test solution.
This standard uses the re-drafting method for reference ISO 7989-2..2007 "Non-ferrous metal plating on steel wire and wire products Section 2
Min. zinc or zinc alloy coating "preparation, and ISO 7989-2..2007 consistency degree is not equivalent.
This standard is proposed by China Iron and Steel Industry Association.
This standard is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC183).
The drafting unit of this standard. National Wire Rope Product Quality Supervision and Inspection Center, Metallurgical Industry Information Standards Institute, Hangzhou Yuhang Prefecture
Metering monitoring center.
The main drafters of this standard. Chen Jianhao, Yang Jinyan, Liu Aihua, Wang Lingjun, Ren Cuiying, Liang Pengshan.
This standard replaced the previous version of the standard release.
GB/T 2972-1982, GB/T 2972-1991.
Test method for copper sulfate of galvanized steel wire
1 Scope
This standard specifies the test principle, test preparation, reagent preparation, test procedure and judgment of galvanized steel wire zinc sulfate test method
Then wait.
This standard applies to the galvanized steel wire zinc layer uniformity test, zinc-aluminum alloy coating wire and galvanized steel wire can also refer to this standard.
2 normative reference documents
The following documents are indispensable for the application of this document. For dated references, the only dated edition applies to this article
Pieces. For undated references, the latest edition (including all modifications) applies to this document.
Preparation of preparations and preparations for use in the test methods for chemical reagents GB/T 603
GB/T 665 Chemical reagents Copper sulfate pentahydrate (Ⅱ) (copper sulfate)
GB/T 674 Chemical reagents Powdery copper oxide
3 test principle
The galvanized steel wire sample is continuously immersed in the copper sulfate solution one or several times for a predetermined time, and the substitution reaction is carried out and gradually dissolves
Zinc layer, and eventually exposed to defects in the surface to determine the uniformity of galvanized layer.
Note. This test is a problem that may reflect unevenness in the thickness of the coating. Therefore, even if the coating quality per unit area meets the relevant requirements,
Exposed surface defects of the coating.
4 Sample preparation
4.1 samples taken from the galvanized steel wire to be tested, the length of about 250mm, properly straightened.
4.2 Specimen surface should be free from any damage, the sample straightening the work of the application of manual, but the wire rope stranded sample can be maintained due to twist
The process of forming the bend, do not have to straighten straight.
4.3 Specimen prior to testing shall be thoroughly degreased with acetone or other suitable degreasing solvent (ethanol, gasoline, ether or petroleum ether) and then steamed
Rinse with water and dry with a cotton or cloth. After degreasing the sample, only allowed to take the end of the non-impregnated. If the wire is corroded or removed
Other chemicals (such as chromates or phosphates) remain on the post-fat surface and should be immersed in 0.2% sulfuric acid solution for 15 s and then rinsed
clean.
5 reagent preparation
5.1 The test solution shall be formulated in accordance with the general provisions of GB/T 603.
5.2 will be 314g copper sulfate crystals (CuSO4 · 5H2O) dissolved in 1L temperature of 20 ℃ ± 2 ℃ in distilled water, copper sulfate crystals should be
Compliance with the analytical requirements in GB/T 665. The solution should be heated until it is completely dissolved. In order to prevent the dissolution time is too long, you can take
The following method. the copper sulfate crushed with water were dissolved, dissolved after the solution is mixed, stirring. If the bottom of the container is left with little undissolved salt
Indicating that the solution is saturated.
5.3 To neutralize the free acid in the solution, add excess base and neutralization (the excess mark is to precipitate at the bottom of the container) in the following manner.
10L solution was added to about 10 g of powdered copper oxide (CuO) and stirred for 24 h and then filtered. The powdered copper oxide should conform to the chemical in GB/T 674
Pure provision.
5.4 Test The test solution is contained in a container such as glass that does not react with copper sulfate. Solution height of not less than 100mm, the container diameter should be
Not less than 80mm.
6 test procedures
6.1 Place the clean sample vertically in the center of the stationary test solution without stirring the solution. The sample shall not be in contact with each other and shall not
Wall contact. (30s or 60s) as specified by the wire product standard, remove the sample smoothly and wash it immediately in water.
Grease, net cloth or brush will be attached to the surface of the zinc layer is not attached to the solid copper and its compounds removed. The temperature during the test is maintained
20 ℃ ± 2 ℃, record the actual temperature.
6.2 Repeat the soaking test as described above until the first surface of the specimen appears to adhere firmly to the metal copper, or the number of times to reach the steel
Silk product standard given the number of times. After the last impregnation test, the sample should be rinsed under running water, wiped with skimmed cotton and soft cloth.
6.3 After several tests, the solution should be replaced when the dissolved zinc concentration in the solution exceeds 5 g/L. Sulfuric acid can be determined by the method specified in Appendix A.
Copper content in copper test solution. In order to save time, in the guarantee of non-contact under the premise of up to six samples can be tested at the same time.
6.4 End of the judge.
A) the sample on the steel base precipitation of bright adhesion of solid metal copper, to reach the end.
B) The following did not reach the end.
1) precipitation of bright adhesion of solid copper, but its single area is not greater than 5mm2;
2) Remove the precipitated copper with a blunt device (such as a knife blade, etc.) and show a zinc layer under copper (to determine whether there is zinc
Layer, where you can drop a few drops of 5% dilute hydrochloric acid containing 0.16% antimony trichloride, with a reactive hydrogen produced in the zinc layer);
3) precipitate copper within 25 mm from the end of the specimen.
7 Judgment principle
The operation of Chapter 6, to achieve the provisions of the wire product standard for the number of qualified, fail to meet the requirements of the wire product standard for the number of
Unqualified, the last test does not count the number of times.
Appendix A
(Informative)
Determination of Zinc in Copper Sulfate Immersion Solution Titration
A.1 Reagents and Materials
Unless otherwise stated, analytical pure reagents and distilled water or comparable purity of water are used in the analysis.
A.1.1 Ammonia (1 1).
A.1.2 Hydrochloric acid (1 1).
A.1.3 xylenol orange solution (0.5%).
A.1.4 Thiourea-sodium thiosulfate solution (10%). Weigh 26 g of sodium pentahydrate or 16 g of anhydrous sodium thiosulfate, add 0.2 g of anhydrous
Sodium carbonate, dissolved in 1L water, add 100g thiourea, dissolved by heating.
A.1.5 Buffer solution. pH 5.4 (weighed 40 g of hexamethylenetetramine in 100 mL of water, plus 10 mL of concentrated hydrochloric acid).
A.1.6 EDTA standard solution [c (EDTA) = 0.02 mol/L].
A.2 Test procedure
A.2.1 Treatment of copper sulfate solution
Accurate absorption of 5mL after galvanized layer uniformity test of copper sulfate impregnated liquid in 250mL Erlenmeyer flask, add ammonia (1 1) to the sink
Starch, and then hydrochloric acid (1 1) to adjust the solution was acidic (that is, copper blue ions disappear blue), and then over 3 drops, plus 20mL thiourea - thio
Sodium sulfate solution, add 2 drops of xylenol orange indicator, slowly add hexamethylenetetramine solution to the solution from yellow to yellow after the excess 3mL, immediately
EDTA standard solution titrated to solution just bright yellow for the end.
A.2.2 Number of measurements
Separate two measurements, whichever is the average.
A.3 Calculation of the results of the analysis
The measured element Zn concentration in ρ, the value of g/L said, according to formula (A.1) calculation.
Ρ =
C (EDTA) x V (EDTA) x 65.38
(A.1)
Where.
C (EDTA) - EDTA standard solution concentration in moles per liter (mol/L);
V (EDTA) - the volume of EDTA standard solution consumed in milliliters (mL);
65.38 - molar mass of Zn in grams per mole (g/mol).