SGCC SPCC CRC G550 Z275 Z100 Z80 Hot Dipped Cold Rolled Galvanized Steel Coil 1000 1200 1250mm Dx51d Dx52D Dx53D Zinc Coated Steel Roll Galvanized Coil Gi

There are two widely used methods for applying zinc coating on steel coils:

Hot-dip galvanising (HDG) technology is used to create a protective layer by immersing a steel strip into a bath of molten zinc. Hot-dip galvanised steel coils can be produced by continuous galvanising lines with non-oxidising annealing furnaces (the Sendzimir method and its variations) or by applying wet or dry flux (the Cook-Norteman method and its modifications). Hot- or cold-rolled non-annealed (full-hard) steel coils are used as feedstock for continuous hot-dip galvanising lines with non-oxidising annealing furnaces. The production process involves electrochemically cleaning, drying and annealing the strip to obtain the required mechanical properties, followed by immersing the material into a bath of molten zinc and controlling zinc thickness. The strip then undergoes forced cooling and finishing (passivation, oiling, levelling, drying and coiling the galvanized coil). When using lines that apply wet or dry flux, feedstock (before it is galvanized) should have the required set of mechanical properties since such lines do not have annealing furnaces. The strip is first degreased with an alkali solution and pickled in acid, following which a smooth layer of flux composed of a combination of zinc chloride, ammonia chloride and various additives is applied to the strip. The strip is then put into a strand furnace with a protective atmosphere, where the flux is dried, and is immersed into a bath of molten zinc. The flux completely removes residual pickling substances and moisture from the metal surface, and the thin film reduces the surface tension of zinc and ensures the best moistening of the metal surface. Hot-dip galvanising technology is fairly universal and is widely used in construction, machine building and other industries. It is used by both large steel mills and re-rollers/coaters.

Electrolytic galvanising is an electro-chemical process in which a layer of zinc is applied in a bath of acid or alkali electrolytes. The main idea of this technology is to use oxidising and reducing reactions, during which electrons move through the electron transport chain, while zinc ions in the electrolyte flow from anode to cathode. This type of coating is usually used for thin-gauge material; the coating thickness is normally 5-12 μm and it accurately follows the shape of the product. The absence of intermediate brittle layers makes electrolytic zinc coating more plastic compared with coating applied via hot-dip galvanizing. Major application areas for such products include automotive, transport and machine building, among others.

Shandong Zhengde Metal Manufacturing Co., Ltd. is a production and sales company integrating hot-rolled steel coils, cold-rolled steel coils, galvanized steel coils, color-coated steel coils, section steel, steel pipes, steel wires, metal mesh, stainless steel, aluminum, copper and other metal products integrated large enterprises. Five production and sales bases have been formed in Binzhou, Liaocheng, Wuxi, Tianjin, Jinan and Tai'an, with more than 100 production lines, 4 nationally recognized laboratories, 2 technical engineering centers, and 5 enterprise technology centers. Products are exported to more than 50 countries and regions such as North America, South America, Europe, Africa, Oceania, Middle East, and Southeast Asia.