Requirements for the thickness and adhesion of zinc coating on galvanized iron wire, as well as laboratory testing and quality control
When the thickness of galvanized iron wire is 3-4 mm, the zinc adhesion should be less than 460g/㎡, that is, the uniform thickness of the zinc layer should not be less than 65 μ M. When the thickness of galvanized iron wire is greater than 4mm, the zinc adhesion amount should not be less than 460g/㎡, that is, the uniform thickness of the zinc layer should not be less than 86 μ M. The galvanized layer of galvanized iron wire is uniformly etched with copper sulfate solution for five times without exposing iron.
The zinc layer of galvanized iron wire should be firmly bonded to the base metal with sufficient adhesion strength, and should not fall or protrude after hammering experiments. Requirement A for the galvanized iron wire to be galvanized: The surface of the galvanized iron wire to be galvanized should be flat and free of dirt that cannot be removed by acid washing. Such as paint, grease, cement, tar, and excessively rotten harmful substances.
The uniformity of galvanized iron wire coating was determined using the copper sulfate solution etching experimental method. When there is a dispute over the adhesion amount, thickness, uniformity, and adhesion of the zinc layer on galvanized iron wire, a sample and the product shall be galvanized under the same process conditions for testing. Products that do not meet the requirements of this standard are considered unqualified. The method for factory inspection of products is: if the first batch fails, it will be inspected according to relevant regulations. If it still fails, the batch of products will be judged as unqualified.
