The production method of galvanized steel plate

Galvanized sheet refers to a steel plate coated with a layer of zinc. Galvanizing is an economical and useful way to prevent corrosion. About half of the world's zinc production is used in this process. Galvanized steel plate is a way to prevent the steel plate from being corrupted and to delay its service life. Coated with a layer of metal zinc in the steel plate, this kind of zinc-coated thin steel plate is called galvanized plate.

What is the use of galvanized sheet according to production and processing methods can be divided into the following categories:

① Hot dip galvanized sheet. The sheet steel is immersed in the melted zinc tank so that its profile adheres to a layer of zinc sheet steel. At present, it is important to adopt continuous galvanizing process production, that is, continuous immersion of rolled steel plates in melted zinc plating tanks to make galvanized steel plates;

② Alloyed galvanized steel plate. This kind of steel plate is also made by hot dipping method, but after the trough, it is immediately heated to about 500 ° C, so that it is naturally coated with zinc and iron alloy. This kind of galvanized sheet has excellent coating adhesion and weldability;

③ Electric galvanized steel plate. This kind of galvanized steel plate made by electroplating has excellent workability. However, the coating is thin and the corrosion resistance is not as good as that of hot-dip galvanized sheet.

④ Single-sided plating and double-sided differential galvanized steel plate. Single-sided galvanized steel plate, that is, the product of galvanized only on one side. It has better compliance than double-sided galvanized sheet in welding, coating, anti-rust disposal, processing and so on. In order to overcome the error of uncoated zinc on one side, there is a galvanized sheet coated with a thin layer of zinc on the other side, that is, double-sided differential galvanized sheet;

⑤ Alloy, composite galvanized steel plate. It is a steel plate made of zinc and other metals such as lead and zinc alloy or even composite plating.

This kind of steel plate not only has excellent rust prevention function, but also has excellent coating function.

1. the significance of hot-dip galvanized strip steel cold-formed thin-wall steel has been widely adopted dark materials, cold bending after the simple rust painting treatment has been put into use, its service life has been limited (generally in about 5 years will show a large area of rust). And our company carefully introduced to the market hot-dip galvanized strip steel, so hot-rolled strip steel as the substrate, through the process of pickling, cold rolling, heating recovery, galvanized and other processes produced into, the product can completely reach the GB510018-2002 "cold-formed thin-wall steel layout skills example" scale, in the construction industry can get a lot of use, It can also be used in automobile, railway locomotive production, warehouse plate production, highway guardrail and other industries.

2. galvanized method of hot-dip galvanized strip steel

Hydrogen recovery galvanizing Hydrogen recovery galvanizing was invented in 1937, and the hydrogen recovery hot-dip galvanizing laid the foundation for modern continuous hot-dip galvanizing. The surface quality and bonding force of the products produced by hydrogen restoration method are better than those by solvent method. Recovery galvanized in the strip after pickling into the heating recovery furnace, using hydrogen to recover the oxide film after pickling, and in the process of heating recovery, the surface layer of the steel plate occurs a layer of sponge recovery layer, into the zinc pot can occur a layer of bidirectional connection force good, average zinc iron alloy layer, greatly increased the zinc layer output, which also determines the galvanizing method of the power loss cost is higher.

3. ammonium chloride solvent galvanizing ammonium chloride solvent galvanizing was invented in 1837. Ammonium chloride solvent method is used to produce products, because ammonium chloride solvent galvanizing has no heating recovery process, its surface quality and the connection force of galvanized layer profile is slightly worse than that of hydrogen recovery galvanizing method. This also determines that the energy loss cost of the galvanizing method is lower than that of the hydrogen recovery galvanizing method.

4. galvanized steel plate galvanized amount is usually 180-220g/㎡, in the wet southern region can respond to the increase of galvanized amount to 275g/㎡ to improve the service life of steel components. The service life of galvanized products is generally 20-25 years.

5. galvanized strip zinc layer characteristics of the galvanizing layer can not form zinc flowers, hot dip galvanizing layer has zinc flowers, its composition process is as follows: When the galvanized strip from the zinc pot into, through the air knife blowing, a large amount of zinc liquid is blown back to the zinc pot, this time the strip steel profile has a pure zinc layer, liquid attached to the steel plate profile, in the steel plate profile to form a large number of crystallization nuclei, with the steel plate rise cooling, so that the crystallization nuclei gradually grow into zinc flowers. The faster the cooling rate, the smaller the zinc flowers, and the slower the cooling rate, the larger the zinc flowers. Flowerless galvanized sheet: In fact, zinc flowers only have the price of play, no actual use cost, the same in terms of anti-corruption is actually not good, in rich countries are fulfilling small zinc flowers and zinc-free galvanized steel.