The purpose, process and production process of hot-dip galvanizing of steel strip

When hot dip galvanized steel strip (coil) is used as a product, it is called hot dip galvanized steel sheet. Hot dip galvanized steel sheet has ideal corrosion resistance, forming, coating and other comprehensive properties, as well as low cost and good appearance. It is mainly used in the construction, automobile and household appliance industries, and is one of the fastest growing steel varieties.

Hot dip galvanizing and its alloys are one of the most common, effective and economical atmospheric corrosion resistant processes for steel materials. The electrochemical potential of the hot-dip galvanized (aluminum) layer is more negative than that of steel materials, and the coating has excellent electrochemical protection properties. The coating is thick and dense, the coating has a strong bonding force with the steel substrate, and the durability is good. The service life of hot-dip galvanized steel with a galvanizing amount of 600g/m2 can reach more than 30 years; the hot-dip galvanized steel layer does not require maintenance during use.

Hot-dip plating is abbreviated as hot-dip plating, which is a process method of immersing the metal to be plated (substrate) material into a low-melting liquid metal or alloy to obtain a protective coating. The outstanding feature of this process is the formation of an alloy layer of metallurgical bonding between the base metal and the bath metal. The metal to be plated (substrate) is generally ordinary carbon steel or alloy steel, but also cast iron and stainless steel. Low-melting-point metals used for hot plating include non-ferrous metals such as zinc, aluminum, lead, tin and their alloys, among which zinc and its alloys are the most widely used hot-dip metals.

The hot plating process is simple and adaptable to the shape and size of the steel. In addition to the steel strip, the hot plating process is also widely used in steel pipes, steel wires and structural parts, and the productivity is high; the galvanized layer is economically compatible with other protective coatings Compared with, it has a strong competitiveness, especially for long-term use of parts, the cost of hot-dip galvanized layer is much lower than that of paint coating. Hot-dip galvanized steel sheet has the largest output, the most varieties and the most versatile applications.

Continuous hot-dip galvanizing of steel strips is hot-dip galvanizing of cold-rolled (hot-rolled) steel strips (coils) on a continuous production line. Steel strips are generally uncoiled, sheared, welded, alkali and/or electrolytically cleaned, and trapped Materials, heating and annealing and reduction, hot dip galvanizing, air knife thickness control, zinc flower or alloy treatment of the coating, cooling after plating, smoothing and drawing straightening, chemical treatment after plating, export looper stock, trimming, A series of processes such as oiling, coiling or shearing produce hot-dip galvanized steel strip (coil).