The basic knowledge and industrial application of galvanized sheet

First, the definition and core value of galvanized sheet

Galvanized sheet is a metal material that is coated with zinc on the surface of steel plates, and its corrosion resistance makes about 50% of the world's zinc production used in this process. The zinc layer can effectively isolate the corrosion of oxygen and moisture on the steel matrix by sacrificing the anode protection principle, which can extend the service life of the steel by 5-8 times.

Second, the innovation process of production technology

1. Evolution of hot dip galvanizing process

From traditional zinc flower technology to modern zinc-free flower technology, the core breakthrough lies in crystallization control. Through water mist cooling and Heurfey zinc spray technology, the density of zinc nuclei can be increased by 300% to form a uniform surface of fine zinc flowers. At present, 90% of new production lines in Europe have adopted the lead-free galvanizing process, and the lead content has been reduced from 0.2% to less than 0.004%.

2. Breakthrough of alloying coating

By thermal diffusion treatment at 500℃, a zinc-iron alloy layer (δ1 phase) is formed, which improves the corrosion resistance by more than 100%. By using laser beam method to monitor the phase transformation process in real time, the iron content can be controlled in the best range of 9-13%. Baosteel and other enterprises have achieved the mass production of 0.18mm ultra-thin alloyed coating.

Iii. Product classification and technical parameters