Different Types of Corten Steel

Corten Steel is a popular type of steel, used specifically in extreme weather conditions due to its high level of weather and corrosion resistance. It is also known as Atmospheric Corrosion Resistant Steel, and its copper and chromium alloying elements provide this level of atmospheric resistance. It is a class of steel alloys that were created to eliminate the need for painting and to form a stable rust-like appearance after being exposed to the elements for several years. While Corten Steel is extremely popular, it can be significantly more difficult to obtain than standard Euronorm designated materials.

Due to its chemical composition, Corten Steel has a distinctive orange color. A rusting layer is formed to protect it when it is exposed to an extreme environment. This Steel gets its properties from careful manipulation of the alloying elements added to steel during the production process. It contains Cr (chromium), Cu (copper), Si (silicon), and P (phosphorus), in varying amounts depending on the properties desired.

Steel rusts in the presence of air and water, producing iron oxide as a byproduct of the corrosion process. Non-weather-resistant steels have a relatively porous oxide layer that can preserve moisture and promote further corrosion. This rust layer delaminates from the surface of the steel after a certain amount of time (depending on conditions), exposing the surface and causing additional damage.

Typical applications for Corten Steel includes: -

(i)                External wall claddings of buildings, and weather strips.

(ii)              Chimneys and other structures under flue gas conditions.

(iii)            Transport tanks.

(iv)             Freight containers.

(v)               Bridges.

(vi)             Heat exchangers.

(vii)           Similar to other steel structures etc.

Types of Corten Steel are: -

Normally, two types of weathering steel are produced. These are also known as Corten A and Corten B. The primary distinction between the types is indeed the amount of P alloyed in the composition. Corten A is typically produced as a sheet or coil and is used in cladding and ductwork. Corten B is more commonly manufactured as a plate, structural section, or tube.

Patina forms more quickly and is darker in color in industrial environments than in rural areas. Chlorides in marine environments inhibit the formation of the protective patina and can prevent the intrinsic behavior of Corten Steel. As a result, it should not be used near the sea or in areas where the air contains a high concentration of chlorides. In the case of open-air structures, the slow corrosion rate is accounted for by adding corrosion allowance to the nominal thickness.