Corten

A particular grade of carbon steel is high strength weathering steel. The most widely known of these steels is COR-TEN® developed by the American USX Corporation; however in some areas it may be known without the hyphen as Corten steel.  In Australia and NZ also known as XLERPLATE (AS/NZ 3678-WR350).

Weathering steel is of particular interest to artists and architects working with constructed steel fabrications intended for a naturally weathered rust patina finish if exposed to the weather for several years.  Corten is alloyed primarily with additions of carbon, silicon, manganese, phosphorus, sulphur, chromium, nickel and copper.

Within the carbon steel group, Corten and other weathering steels react with oxygen to produce a rust oxide on untreated surfaces. In normal carbon steels the oxidisation process can eventually lead to the oxide conversion of the steel’s entire fabric – potentially resulting in structural collapse. The alloying elements added into weathering steels (in particular the copper and chromium components), encourage a very dense oxide layer to develop on the exposed surfaces; this exceptional density effectively inhibits any deeper corrosive penetration into the fabric of the metal. Dependent upon the ambient atmosphere and conditions the steel is exposed to, a rich rust oxide patina naturally develops without unduly compromising the longevity of the artwork.