What are the characteristics of coil coating industry?
Galvanized sheet materials can be divided into categories according to cold-rolled and hot-rolled galvanized sheet galvanized sheet. The most common cold-rolled galvanized sheet, its raw materials after hot rolling and cold rolling process is also pickled. The thickness of the small and relatively smooth surface, suitable for most purposes. But with the economic and technological development, many occasions require thicker galvanized sheet. If its surface do not ask, you can use the direct hot-rolled plate galvanized.
Hot-rolled galvanized sheet thickness is generally 2 ~ 4mm, width 1000 ~ 1600mm, and cold-rolled galvanized sheet specifications of the coverage area of the cross is not great, so compatibility is not too strong. Its biggest advantage is the raw material without cold working, so the price is cheaper, lower production costs. The process is characterized by the use of pickling process, instead of caustic, no recrystallization annealing in a furnace, as long as you can reach the iron oxide reduction temperature, typically 550 ℃. Its products are characterized by a high roughness because the original plate, galvanized thick coating process, small spangle, thus galvanizing the amount is often larger, thinner coatings produce products more difficult. At the same time, the grain has not been cold rolling hot rolled sheet broken refined, poor mechanical properties, can not produce deep and ultra-deep leveling leveling products.
To overcome the poor surface quality of the hot rolled sheet drawback at present, some enterprises to adopt a flat hot-rolled sheet after pickling reinvested after galvanizing galvanizing line, due to the increase of a smooth process, the surface roughness and uniformity spangle It has been improved, and can produce slabs galvanized products