What makes weathering steel weather resistant is its special chemical composition and make-up. Weathering steel is more resistant to corrosion than most steels because the surface of the material oxidizes to form a protective layer of bronze-colored rust under frequent alternating wet and dry conditions. Unpainted weathering steel requires very little maintenance and the bronze color will prevent the steel from rusting further.
Weathering steel is also specially added to the alloying elements, in the role of the alloy corrosion will become slow, and has a variable corrosion inhibition effect, weathering steel surface of the protective layer will be with the weathering effects of slow growth regeneration. In short, the steel is to form a protective layer by generating rust on the surface.
