What Is Galvanized Steel Sheet?

Galvanized steel is a welded steel plate with a hot-dip galvanized or galvanized layer on the surface. It is generally widely used in construction, home appliances, vehicles and vessels, container manufacturing, and electrical and mechanical industries.

Development history of galvanized steel

The first continuous hot-dip galvanized strip production line was established in the United States in 1937, and the first continuous galvanized strip production line was established in the United States in 1942. It has been in industrial production for more than 70 years.

Hot-dip galvanized products are widely used in construction, home appliances, vehicles and vessels, container manufacturing, mechanical and electrical industries, etc., and they are almost involved in all fields of clothing, food, housing and transportation. In recent years, the world s demand for galvanized steel has been increasing, and output has also grown rapidly. In major steel producing countries such as the United States and Japan, hot-dip galvanized steel accounts for 13% -15% of steel.

Recently, the automotive industry has paid more and more attention to the service life of materials, and painted cold-rolled steel sheets can no longer meet the requirements of corrosion resistance. In this case, hot-dip galvanized sheet, which has excellent corrosion resistance and low cost, has begun to be popular with automobile manufacturers.

The biggest advantages of coated steel plates are excellent corrosion resistance, paintability, decoration, and good formability. In recent years, the amount of coated steel sheets in automobiles has been increasing, and has become the main body of automotive thin plates. Countries around the world are studying how to expand the variety and specifications of coated plate, improve the coating process and thereby improve the quality of the coating, that is, corrosion resistance, resistance to powder peeling, coating, and welding. The formability of the coated plate is always an important aspect of its application, which mainly depends on the performance of the substrate, the coating process and performance and the forming process conditions. Good application effects can be achieved through the combination of comprehensive advanced technology.

Production Status of Galvanized Steel

China's hot-dip galvanizing production has been lagging behind. From the 1950s to the 1960s, 13 single-sheet steel flux hot-dip galvanizing units were successively built, with a capacity of 100,000 t / a. However, due to the shortcomings of low output, high cost, poor quality, environmental pollution and poor economic benefits, Stopped and changed production. Only in the late 1970s did China begin to build large-scale broadband hot-dip galvanizing units.

Hot-dip galvanized strip has always been a scarce variety in our market. Since the mid-1990s, about 800,000 to 1,000,000 tons have been imported from abroad every year. With the development of the domestic economy, especially the development of automobiles, home appliances and construction industry, the demand for galvanized strip steel has also greatly increased. Over the past two decades, China has built a number of production lines with an annual output of more than 100,000 tons, but the hot-dip galvanizing units that belong to low-level traditional technologies in terms of process flow, equipment composition, and product varieties cannot meet China's quality and quantity The needs of economic construction and development still require the construction of new hot-dip galvanizing lines to meet market needs.

Since the 1990s, China has made great progress in the production of galvanized steel sheets, and the domestic galvanized sheet processing capacity in China and under construction has reached nearly 3 million tons. The market share of domestic galvanized sheet has increased rapidly, from about 27% in 1996 to about 59% in 1998. The main domestic manufacturers are Baosteel, Wuhan Iron and Steel, Panzhihua Iron and Steel, Handan Iron and Steel, and Benxi Iron and Steel. The total production capacity of these five companies has exceeded 1.3 million tons.

The main gap between China's existing hot-dip galvanizing units and foreign levels is that most units have no pre-cleaning equipment and it is difficult to guarantee the quality of the galvanized surface; the existing finishing machines are relatively simple two-roller finishing machines (pan The steel is four rolls), which cannot improve the mechanical properties of the strip, especially the deep-drawing performance; the existing varieties are all single galvanized sheet, with only a small amount of alloyed sheet, which is far from meeting the needs of the market.

The hot-dip galvanized steel plates produced by Chinese manufacturers are mainly used in building materials, light industry, agriculture, transportation and other industries. Due to the limitations of the existing hot-dip galvanizing equipment conditions, process technology and the performance of the original plate, the actual production of galvanized sheet available for the automotive industry is very small.

Features of galvanized steel: Galvanization can effectively prevent steel corrosion and prolong service life. Galvanized sheet steel (thickness 0.4 1.2mm) is also called galvanized iron sheet, commonly known as white iron sheet. Galvanized steel is widely used in construction, vehicles, home appliances, daily necessities and other industries. ^[2]