Galvanized steel coils are rolled under recrystallization, but it is generally understood to be rolling using cold rolled materials. Aluminum cold rolling is divided into plate rolling and foil rolling. Thicknesses above 0.15~mm are called plates, and thicknesses below 0.15~mm are called foils. In Europe and America, 3~6 continuous rolling mills are used as cold rolling equipment.
Wholesale Galvanized Steel Coils Production Process
Since the production process does not involve heating, there are no defects such as scale and iron oxide that often occur in hot rolling. The surface quality is good, and the smoothness is high. Moreover, cold rolled products have high dimensional accuracy. The properties and structure of the products can meet some special usage requirements, such as electromagnetic performance, deep drawing performance, etc.
Materials of Wholesale Galvanized Steel Coils
Galvanized steel coils have different surface conditions due to different handling methods in the coating process, such as regular zinc coils, fine zinc coils, smooth zinc coils, zinc-free coils, and phosphatized surfaces. Wholesale galvanized steel coils should have a good appearance and must not have defects harmful to product use, such as bare spots, holes, cracks, dross, excessive zinc coating, scratches, chromate dirt, and white rust.
Wholesale Galvanized Steel Coils can be classified as follows based on production and processing methods
Hot-dip galvanized steel coils
Thin steel coils are dipped into a molten zinc bath so that their surface adheres to a layer of zinc. Currently, the continuous galvanizing process is mainly adopted, which means continuously immersing coiled steel sheets in a bath of molten zinc to produce galvanized steel coils
Alloyed galvanized steel coils
This type of steel coil is also manufactured using the hot-dip method, but it is heated to approximately 500℃ after being taken out of the bath to form a zinc-iron alloy film. This kind of galvanized steel coil has good paint adhesion and weldability
Electro-galvanized steel coils
Electroplating is used to produce this type of galvanized steel coil that has good workability. However, the coating is thinner and its corrosion resistance is not as good as hot-dip galvanized steel coils
Single-side and double-side differential galvanized steel coils
Single-side galvanized steel coil products have zinc coating on only one side. They have better adaptability than double-side galvanized steel coils in terms of welding, painting, rust prevention, processing, etc. To compensate for the shortcomings of non-galvanized sides, there is a type of galvanized steel coil coated with a layer of zinc on the other side; this is a double-sided differential galvanized steel coil
Alloy and composite galvanized steel coils
Made of zinc and other metals such as lead and zinc to form alloy or even composite-coated steel coils. These steel coils not only have excellent rust resistance but also have good paintability. In addition to the five types mentioned above, there are also pre-painted galvanized steel coils, printed coated galvanized steel coils, and polyvinyl chloride laminate galvanized steel coils. However, the most commonly used type currently is still hot-dip galvanized steel coils. Galvanized steel coils can be further classified by use into general purposes, roofing, building exterior panels, structural use, tile ridges, drawing, and deep drawing types.
The reason why galvanized steel coil surfaces are coated with a layer of zinc is in fact to prevent steel from oxidizing in the presence of water and other oxides in the air, leading to corrosion. Coating with a layer of zinc protects the steel better. Wholesale galvanized steel coils have two major advantages: adhesion and weldability. Due to these two advantages, they are widely used in construction, industry, automobile industry, and commerce. Another important characteristic is corrosion resistance, which has a significant effect on the manufacture of home appliance shells.
