What Is Aluminized Steel?

Aluminized steel plate The surface of carbon steel is plated with a layer of pure aluminum or an aluminum-silicon alloy containing 5% to 10% silicon. The methods of aluminum plating are: hot plating, electrophoresis, and vacuum evaporation. Among them, hot plating is the most widely used method. Aluminized steel has good high temperature oxidation resistance, does not change color for a long time at 450 , and the maximum use temperature can reach 750 . It also has good resistance to atmospheric corrosion, especially against the corrosion of gases such as SO ₂ , H ₂ S, and CO ₂ . Corrosion resistance is 3 to 6 times that of galvanized steel. It is mainly used in automobile exhaust systems, heat-resistant appliances, beverage cans, etc.

There are two types of aluminized steel sheets: one is called category 1, which is mainly heat resistant and can withstand high temperatures around 640 ° C. This aluminum-plated steel sheet is plated with an Al-Si alloy (containing 6 to 8.5% Si) in a thickness of 20 to 25 microns on a low carbon steel sheet. The other is called category 2, which is mainly corrosion resistance, and its coating thickness is 2 to 3 times that of category 1. No matter which type is formed by hot dip plating

Aluminized steel is the combination of the two most widely used metals in our daily life, iron and aluminum. This kind of steel plate can make full use of the characteristics of two metals and constitute a steel plate with special properties. Because it has good corrosion resistance,

Heat radiation reflectivity is another feature of aluminized steel sheet in controlling, blocking and suppressing heat radiation. In a short time, its performance can be comparable to pure aluminum and better than galvanized steel. According to tests, after 4 years of outdoor use in urban suburbs, the galvanized steel sheet's heat radiation reflection ability has been reduced to only 5%, which is approximately a black body that absorbs all radiant heat, while the aluminized steel plate's reflection ability is still 55%.

Aluminized steel is also very good in terms of high temperature oxidation resistance. When the surface temperature reaches about 510 ° C, the aluminum plating layer can prevent the steel plate from being oxidized and does not change color by itself. Therefore, it is especially suitable for heat-resistant facilities subject to corrosion by corrosive condensate or other combustion by-products. At a temperature of 510 to 677 ° C, although the aluminum-iron-silicon alloy is somewhat blackened, the aluminum coating can still protect the steel plate very well. The melting temperature of the steel sheet base layer is 1580 ° C, which is lower than that of the aluminum layer.

The use of aluminized steel is relatively wide. For automobiles, it is used for heat-resistant parts of exhaust pipes, mufflers and body parts. The furnace is used in heat exchangers, furnace reflectors, furnace oil tanks, baking boxes, furnace bodies, incinerators, chimneys and dryers. Containers are used for refrigerated containers, special oil tanks, article tanks and plumbing equipment. For construction, it is used for roofs, window frames, wall panels, outdoor facilities, cabinets, household appliances, lamps, billboards and outdoor facilities.

The thickness of the aluminized steel sheet produced in the world is 0.27 ~ 2 mm, the width is 558 ~ 1219 mm, the length is 4 meters, and the thickness of the coating is 120 g / m ² . Aluminized steel sheet was created by American Amco Corporation more than forty years ago. Compared with other coated steel plates, its history is relatively short. The production process uses the hot-dip galvanizing method, which is basically similar to the hot-dip galvanizing method. The main difference is the melting tank. The temperature of the aluminum melting tank is about 700 ° C, while the temperature of the zinc melting tank is only 450 ° C. Since the use of ceramic magnetic aluminum tanks, the production of hot-dip aluminized strip steel has developed rapidly. There are two types of special aluminum-plated and aluminum-zinc combined units in the world. The annual output of a special aluminum-plated unit can reach about 250,000 tons. In addition to the special units built in the United States, in recent years, new dedicated units have also been put into production in West Germany and Australia, so the world s output of aluminized steel sheets has increased year by year. Our country needs this product very much, but it is lacking. It can be considered to add an aluminum plating device to the existing and newly-built galvanized steel sheet production lines to meet the demand, and then expand the production as needed. ^[2]