Cor-Ten Steel

What is Cor-Ten Steel?

Weathering steel, often referred to by the genericized trademark COR-TEN steel and sometimes written without the hyphen as corten steel, is a group of steel alloys which were developed to eliminate the need for painting, and form a stable rust-like appearance if exposed to the weather for several years.

U.S. Steel holds the registered trademark on the name COR-TEN. The name COR-TEN refers to the two distinguishing properties of this type of steel: corrosion resistance and tensile strength.

Weathering refers to the chemical composition of these steels, allowing them to exhibit increased resistance to atmospheric corrosion compared to other steels. This is because the steel forms a protective layer on its surface under the influence of the weather.

The corrosion-retarding effect of the protective layer is produced by the particular distribution and concentration of alloying elements in it. The layer protecting the surface develops and regenerates continuously when subjected to the influence of the weather. In other words, the steel is allowed to rust in order to form the protective coating.

The famous statue “The Angel of the North” is made from more than 200 tons of Cor-Ten steel.