Galvanized steel plate is to prevent the surface of the steel plate from corrosion to extend its service life, coated with a layer of metal zinc on the surface of the steel plate, zinc coated steel plate called galvanized plate.
Zinc is a very reactive metal that oxidizes extremely easily, but instead of a loose powder like iron oxide, zinc oxide has a dense outer layer that prevents further oxidation of the zinc inside.
When the surface of galvanized steel is damaged, exposing the inner surface of iron, zinc is more reactive than iron, so according to chemical battery theory, zinc will oxidize before iron, thus protecting the iron layer from damage.These two are integrated, it is the truth that galvanizing steel plate protects.
Galvanized sheet is mainly used in construction, home appliances, automobile, machinery, electronics, manufacturing light industry and other industries.
According to the production and processing methods can be divided into the following categories:
(1) hot dip galvanized steel sheet.Dip the sheet steel into the melted zinc bath
To make the surface adhere to a layer of zinc sheet.At present, the main use of continuous galvanized process production, that is, the coil of steel plate continuously immersed in the melting zinc plating tank made of galvanized steel plate;
(2) alloy galvanized steel plate.This kind of steel plate is also made by hot dip method, but after the trough, it is immediately heated to about 500℃ to form alloy film of zinc and iron.The galvanized sheet has good coating tightness and weldability.
(3) electric galvanized steel plate.This galvanized steel sheet is made by electroplating with good processability.But the coating is thinner, the corrosion resistance is not as good as hot dip galvanized sheet;
(4) single-sided plating and double-sided galvanized steel.Single-sided galvanized steel, that is, only on one side of the product galvanized.In welding, coating, anti-rust treatment, processing and other aspects, has better adaptability than double-sided galvanized sheet.
In order to overcome the disadvantage of single side without zinc coating, there is a zinc plate coated with thin layer of zinc on the other side.
(5) alloy, compound galvanized steel plate.It is made of zinc and other metals such as aluminum, lead, zinc alloy and composite plate.This kind of steel plate not only has the remarkable antirust performance, but also has the good coating performance;
In addition to the above five, there are color galvanized steel plate, printing coating galvanized steel plate, PVC laminated galvanized steel plate.But at present the most commonly used is still hot dip galvanized sheet.