COR-TEN has served as weathering steel (atmospheric corrosion- resistant steel). Corten steel plate has successfully overcome rust, steel's most weakest. When exposed to the atmosphere without painting, corten steel begins to rust in the same way as ordinary steel. BUT soon the alloying elements in COR-TEN cause a protective surface layer of the fine-textured rust to form, thereby suppressing corrosion rate. Since its development in 1993, the COR-TEN has been used in every field where steel applied, such as bridges, railway vehicle and buildings. At present, COR-TEN are attracting attention as being suited for resources and environmental concerns as well as reducing life-cycle costs.

Corten Steel - Rust Surface with Protective Layer

Corten is a type of steel that naturally weathers over time, and developing an attractive and protective rust layer. It is really a paradox, as although it is rusted, to a degree, the surface actually has a layer that protects against further corrosion. In other words, the steel is allowed to rust in order to form the protective coating. This protective layer develops due to the elements that are active in the alloys of the steel. It regenerates continuously when subjected to the influence of water and oxygen.

Rusting Process

The image to the right shows how the corten steel cladding will look when it first arrives and before the protective layer has started forming, looking much like any normal steel sheet . If you wish, you can speed up the rusting process by using a cloth and rubbing the surface with salt and/or vinegar.