The name Cor-Ten comes from the initials of the two English terms used to file the patent in 1932: CORrosion resistance and TENsile strength.
The word “CorTen” is the trademark name given to a weathering steel alloy material originally produced by United States Steel.
CorTen is a low alloy steel with 0,2 - 0,5% di copper, 0,5 - 1,5% di chromium e 0,1 - 0,2% di phosphorus.
CORTEN thickness 5 mm R 25, Bressanone - Realized by Graepel Italiana Spa
The great success of CorTen can be attributed to its two main characteristics: mechanical strength and controlled oxidation.
This two features along with its aesthetic quality are the keys of the success of this material, which lately has become more and more appreciated by architects and designers.
Its patina prevent the progressive corrosion process in the internal part of the metal providing a smooth and resistant surface, with unique chromatic characteristics.
In the presence of moisture and air, all low alloy steels have a tendency to rust, the rate of which depends on the access of oxygen, moisture and atmospheric contaminants to the metal surface. As the process progresses, the rust layer forms a barrier to the ingress of oxygen, moisture and contaminants, and the rate of rusting slows down.
The rust layers formed on most ordinary structural steels are porous and detach from the metal surface after a certain time, and the corrosion cycle commences again. Hence, the rusting rate progresses as a series of incremental curves approximating to a straight line, the slope of which depends on the aggressiveness of the environment.
The color changes during the oxidation process: from an initial orange color to a brown-reddish as the patina stabilizes. Under normal weather conditions, the oxidation process is completed in 18-36 months, with a thickness decrease of 0.05 mm.