The use of CorTen steel in public spaces creates a warm, natural look. CorTen steel can be applied outdoors without any treatment, thus avoiding environment-unfriendly zinc or chemical coatings.Corten Steel is a special steel originally developed for bridge building and skyscraper construction due to its incredible strength. When the steel weathers it develops a dense oxidisation layer which protects the blue steel inside. If this protective layer is compromised, it will simply form a a new skin to protect itself. This makes Corten Steel extremely durable and gives it far higher resistance to atmospheric corrosion than other steels.Most unalloyed steels have a porous oxide top layer, which holds moisture, resulting in rust. This rust layer will eventually flake off, exposing a new oxide layer to rust. As this process is repeated, eventually the steel with rust through.