Characteristics of weathering steel
Corten A steel sheet: this product refers to low alloy structural steel with protective rust layer and atmospheric corrosion resistance. Corten A steel sheets can be used to manufacture steel structures such as vehicles, bridges, towers, and containers. Compared with ordinary carbon steel, weathering steel Corten A has better corrosion resistance in the atmosphere. Compared with stainless steel, weathering steel Corten A is added with a small amount of alloying elements, such as phosphorus, copper, chromium, nickel, molybdenum, niobium, vanadium, titanium, etc. The total amount of alloying elements only accounts for a few percent, and it is resistant to atmospheric corrosion and seawater corrosion. Greatly improve.
The principle of corrosion resistanceAfter adding trace elements such as phosphorus, copper, chromium, and nickel to steel, a dense and highly adherent protective film is formed on the surface of the Corten A steel sheet, preventing the corrosion from spreading and developing, and protecting the substrate under the rust layer. Slow its corrosion rate. An amorphous spinel oxide layer of about 50 μm to 100 μm thick formed between the rust layer and the substrate is dense and has good adhesion to the base metal. The presence of this dense oxide film prevents oxygen and The infiltration of water into the steel substrate slows down the development of rust into the steel material and greatly improves the atmospheric corrosion resistance of the steel material. During the use of weathering steel Corten A in contact with the atmosphere, the surface of the metal substrate forms a dense, highly adherent amorphous oxide protective film, and the color gradually changes from rusty red to dark blue, and finally to dark purple, and no longer rusts. When stabilized, this protective film effectively blocks the intrusion of corrosion and prolongs the service life of the component. An independent foreign scientific research institution compared the corrosion resistance of Corten A steel with ordinary carbon steel in different environments, showing the good weather resistance of corrosion-resistant steel. High-quality weathering steel Corten A has an average corrosion depth of about 0.1 to 0.2 mm after 16 years in a seaside environment, and about 0.02 to 0.04 mm in industrial areas and rural areas.
It is generally believed that the weathering resistance of weathering steel Corten A is 5-8 times that of general structural steel, and its corrosion resistance life can reach more than 30 years even under the condition of bare installation.
