The protective duration of the galvanized layer of large roll galvanized wire is closely related to the thickness of the coating. Generally speaking, in relatively dry main gas and indoor use, and in harsh environmental conditions, the thickness of galvanized layer needs to be very high. Therefore, the environmental impact should be considered when choosing the thickness of galvanized layer. After passivation treatment of galvanized layer, a layer of bright old and beautiful color passivation film can be generated, which can significantly improve its protective performance.
There are many kinds of galvanized solution, which can be divided into cyanide plating solution and cyanide plating solution. Cyanide galvanizing solution has good dispersion and covering ability, coating crystallization is smooth and fine, simple operation, wide application range, has been used in production for a long time. However, because the plating solution contains highly toxic cyanide, the gas escaping in the plating process is harmful to the health of workers, and the waste water must be treated strictly before discharge.
Zinc is a silver-white metal, brittle at room temperature, soluble in acid and alkali, known as amphoteric metal. Pure zinc is more stable in dry air, and small in humid air or water containing carbon dioxide and oxygen. A thin film layer of basic zinc carbonate will be formed on the surface, which can delay the corrosion rate of zinc layer. The corrosion resistance of galvanized layer in aqueous solution of acid, alkali and sodium chloride is relatively strong. It is also not resistant to corrosion in atmospheres containing carbon dioxide and hydrogen sulfide and in Marine atmospheres; In high temperature and high humidity air and containing organic acid atmosphere is small, galvanized layer is also easy to be corroded.
Post time: 07-03-23