The demand for galvanized coil construction and light industry is the main market for galvanized steel, which accounts for about 30% of galvanized steel. According to the speed of national economic development and the consumption base, the demand in the first half of the year is about 4 million tons, equivalent to 180 thousand tons of refined zinc consumption.
Also, from the consumption of galvanized steel in the home appliance industry, air conditioners are the main products of galvanized steel consumption. The back plate of the air conditioner, the back plate of the cabinet, the inner parts, the outer shell of the outdoor machine and the interior are all made of galvanized sheet, and the average one air conditioner needs to consume 22 kilograms of galvanized sheet. In addition, each washing machine consumes 8 kilograms of galvanized steel, and each refrigerator consumes 3 kilograms of galvanized steel. Zinc plating is a surface treatment technology for plating a layer of zinc on the surface of metal, alloy or other materials to make it beautiful and rust proof. The main method is hot-dip galvanizing.
Zinc is soluble in acid and soluble in alkali, so it is called amphoteric metal. Zinc does not change almost in the dry air. In moist air, a dense zinc carbonate film is formed on the surface of zinc. In the atmosphere containing sulfur dioxide, hydrogen sulfide and marine atmosphere, the corrosion resistance of zinc is poor, especially in the atmosphere of high temperature and high humidity containing organic acid, and the zinc coating is easily corroded. The standard electrode potential of zinc is -0.76V. For steel matrix, zinc coating belongs to anodic coating. It is mainly used to prevent corrosion of iron and steel. Its protective performance is closely related to the thickness of the coating. Zinc coating is passivated, dyed or coated with light retaining agent, which can significantly improve its protective and decorative properties.
The automobile industry is also a major industry of galvanized sheet consumption, and its weight is much heavier than that of the household electrical appliance industry. Since 2006, China's automobile production has increased rapidly, especially in saloon cars. In accordance with the calculation of 350 kilograms of galvanized sheet for each car, the demand for galvanized sheet in China's auto industry in 2007 will be around 3 million 100 thousand tons, consuming 140 thousand tons of fine zinc, up by more than 20% over 117 thousand tons in 2006.
If there is a long term and a lot of words, only the color coated steel plant needs most. Household appliances and automobiles are also used, but the quantity is small and the demand is very high. Very few factories have met the requirements. Now the construction industry also needs a large number of galvanized plates to make ventilation pipes. A medium-sized building needs more than 2.5 million square meters, with a total of nearly 200 tons of various specifications, which is not a loss in the process. There are many large projects to be built nationwide or Beijing, and the demand is very large.