Corten B – a weather resistant steel which is better suited for heavy and load bearing structures.
The material forms its own protective layer when exposed to atmospheric elements. Essentially, the top layer corrodes which then protects the steel beneath it. The natural finish does not normally require any form of maintenance such as painting, which makes the material a highly cost effective alternative to other structural steels.
Painting and maintenance will be required if the structure is is continually wet as a protective layer will not form. An good example is where the base of the structure meets with the ground or is partially submerged.