Corten steel is a kind of alloy steel, which can form a relatively dense rust layer on the surface after exposure for several years, so it does not need to be protected by paint. Different stainless steels can be completely rust-free. Corten steels only have surface oxidation and do not penetrate into the interior. They have corrosion protection characteristics like copper or aluminium. Corten steel is a kind of low carbon steel, which contains other alloying elements mixed with carbon and iron atoms. Compared with typical low carbon steel grades, these alloying elements make weathering steel have better strength and corrosion resistance.