Corten steel is a steel with phosphorus, copper, chromium and nickel-molybdenum added to it. These alloys improve the resistance of corten steel to atmospheric corrosion by creating a protective patina on its surface Corten steel is an exceptionally strong steel grade first used in the heavy industry. Due to its copper content, it has become beloved by the architectural world for the rust-coloured finish it develops..
How does corten steel rust? The composition of rusty steel Corten steel is steel made with added phosphorus, copper, chromium, and nickel-molybdenum. All of these alloys increase the resistance of corten steel to atmospheric corrosion by creating a protective patina on its surface.
The formation of the patina Corten steel corrodes the same as other steels, except that it doesn't regenerate. When the alloys mentioned above are added, rust becomes more stable and adheres better. The sequence of wet and dry periods acting on corten steel leads to corrosion until a layer of resistant and protective metal oxide is formed. The steel becomes less permeable as the layer matures and no longer gets marks.