Cold galvanized is in the plating tank through the current unidirectional zinc gradually plated on the metal surface, production speed is slow, uniform coating, thin thickness, usually only 3-15 microns, bright appearance, poor corrosion resistance, generally a few months will rust. Compared with electrogalvanizing, hot galvanizing has lower production cost and less impact on the environment than electroplating.
For the specification of galvanized wire, the galvanized wire produced by our factory can range from No.8 to No.22, which refers to the BWG standard, that is, from about 4mm to 0.7mm, which can basically cover the type required by customers. As for the raw material of galvanized wire, normally, we use Q195 mild steel, and some factories will also use SAE1006 or SAE1008. The following is the zinc coating, for galvanized wire, this thing is more important, the general zinc coating is about 50g/m2 to 80g/m2, some customers need high zinc galvanized wire, zinc coating can reach 200g/m2 to 360g/m2. The tensile strength of galvanized wire is usually 350n/m2 to 800n/m2. Then there is the packaging specification of galvanized wire. The specifications of small rolls of galvanized wire are 50kg/ roll, 100kg/ roll and 200kg/ roll. Of course, there are large rolls of galvanized silk, the weight can reach 300kg/ roll or 800kg/ roll.
Galvanized wire to galvanized uniform, a body is now its cross section, the second is the longitudinal uniformity. In the actual operation process, such as the jitter of steel wire, the surface of the pot scum and other reasons will cause galvanized wire surface galvanized layer accumulation, should try to solve the problem.
Strictly control the pH value of large roll galvanized wire bath, research shows that the size of the bath pH value directly affects the quality of steel wire coating, improper control of pH value will cause loose coating. When the pH value is greater than 3, the steel wire coating has burr caused by fine dendrites, and the surface is not smooth. The current density is strictly controlled. From the microscopic morphology, the higher the current density, the larger the zinc layer grain deposition, the less dense the corresponding zinc layer.
Hot – plated wire average performance: reflected in its cross – section, longitudinal uniformity. In the actual process of operation, such as steel wire jitter, the surface scum plating pot and other reasons will cause the surface of galvanized wire galvanized layer accumulation, should strive to solve the problem. In addition to these reasons, we should pay attention to the tooling and process must be stable, and regular testing should be done to ensure the uniformity of the galvanized layer.
Paint on the galvanized layer, the binding force between each other and the baking temperature of the paint has a great relationship, after galvanized coating alkyd paint, adhesion is no problem. Galvanized amino paint, paint adhesion is not good. Do two bottom two surface, adhesion is ok, if the two bottom two surface to two bottom three surface, that is, more paint, more baking once, again test adhesion is very poor, poor to the paint from the galvanized layer of pieces torn off.