Corten steel are a family of mild steels that contain additional alloying elements mixed with carbon and iron atoms. But these alloying elements give weathering steel better strength and higher corrosion resistance than typical mild steel grades. Therefore, corten steel is often used in outdoor applications or in environments where ordinary steel tends to rust.
It first appeared in the 1930s and was mainly used for railway coal carriages. Weathering steel (the common name for Corten, and weathering steel) is still widely used for containers due to its inherent toughness. Civil engineering applications that emerged after the early 1960s took direct advantage of Corten's improved corrosion resistance, and it didn't take long for applications in construction to become apparent.
The properties of Corten result from careful manipulation of the alloying elements added to the steel during production. All steel produced by the main route (in other words, from iron ore rather than scrap) is produced when iron is smelted in a blast furnace and reduced in a converter. The carbon content is reduced and the resulting iron (now steel) is less brittle and has a higher load capacity than before.
Most low alloy steels rust due to the presence of air and moisture. How quickly this happens will depend on how much moisture, oxygen and atmospheric pollutants it comes into contact with the surface. With weathering steel, as the process progresses, the rust layer forms a barrier that prevents the flow of contaminants, moisture and oxygen. This will also help to delay the rusting process to some extent. This rusted layer will also separate from the metal after a while. As you will be able to understand, this will be a repeating cycle.