Rusting principle and rusting treatment of weathering steel plate
Weather-resistant steel plates are mainly corrosion resistant and have good welding performance. The current technology of this steel plate is relatively mature in several large-scale medium plate factories, such as Baosteel, Wugang, Jinan Iron and Steel, Shougang, etc. If you need this product, it depends on which one you are Area, and then look for spot in nearby steel mills. By adding weather-resistant elements, the steel material forms an oxide layer of about 50-100μm thick between the rust layer and the substrate and has good adhesion to the substrate metal.
Due to the existence of this dense oxide film, oxygen and water in the atmosphere are prevented from penetrating into the steel matrix, which slows down the development of rust to the steel material in depth, thereby greatly improving the atmospheric corrosion resistance of the steel material. Weathering board has good resistance to atmospheric corrosion, in which alloying elements play a decisive role, including obstacles to the growth of rust layers; prolongs the crystallization of rust; obstacles to cracks and defects. Carbon is detrimental to the atmospheric corrosion resistance of steel. Affect welding, cold brittleness and stamping performance. The carbon in weathering board is controlled below 0.12%. Copper is resistant to atmospheric corrosion. Copper forms an anti-rust barrier layer on the steel substrate, but copper forms an intergranular effect between crystals, which is prone to cracks. Phosphorus is one of the main elements to improve atmospheric corrosion resistance *.
Weathering steel is a kind of low alloy steel between ordinary carbon steel and stainless steel. The content of alloying elements in weathering steel is not high, but the performance is very good. Weathering steel is widely used in various places such as railways, landscapes, bridges, etc. , We invited professionals from Anyang Shangpu Industry to explain the rusting principle and rusting treatment of weathering steel for us.
At the initial stage of corrosion of weathering steel, a denser rust layer will be formed on the surface than ordinary carbon steel, and the corrosion of weathering steel will have relatively few cracks and holes. There is no difference between the local delamination and corrosion products of carbon steel and weathering steel. The main difference between them is the role of alloying elements in the rust layer. There are precipitation of Cu and Cr alloy elements in the weathering steel rust layer. The precipitated elements can gather at the cracks of the weathering steel to resist the intrusion of moisture and harmful ions in the atmosphere and prevent further corrosion of the weathering steel.
After the weathering steel surface is corroded, a certain method needs to be used to solidify the rust layer on the surface. It is necessary to suppress the rust that flows out in the initial stage of the steel to stabilize the weathering steel. The appearance is similar to the general coating, but the general coating is to block the outside air and the outside of the steel to inhibit rust, while the rust stabilization It promotes the stabilization of rust. There is a big difference in function. If the coating deteriorates after the application of the coating, it will cause the paint to peel off, which will cause rust, and it will have to be painted again in order to maintain the beautiful appearance. However, the rust stabilization treatment method slowly melts the film, so that the generated rust stabilization gradually expands to all, covering a layer of film on the steel surface, and no maintenance is required.