Weather resistant steels are high strength, low carbon structural steels including small amounts of alloying elements such as copper, chromium, nickel and phosphorus. As a result of these alloying elements and effects of oxygen and humidity, a protective oxide layer is formed on the surface of the steel. The oxide layer prevents the steel from corroding beneath the surface. The thick oxide layer regenerates itself in case of surface damage. The patinated brown-orange appearance of weather resistant steel is formed when the steel is exposed to various weather conditions like humidity and drought. It takes approximately 18-36 months until the protective layer is formed under normal weather conditions. Weather resistant steels are cold formable and great to weld.
Weather resistant steel is commonly known as CORTEN (CORrosion resistance – TENsile strength).
Corten A: steel includes more phosphorus and is most commonly used in architectural structures
Corten B: more suitable for applications requiring high strength due to better impact test results at low temperatures
The products made of weather resistant steel have a long lifespan in even the most challenging weather conditions. Especially architects have found multiple ways to use weather resistant steel when – alongside the structures and costs – the aesthetics of the buildings need to be taken into consideration. The utilization of weather resistant steel reduces the need and thus the costs related to surface treatment. Also thet environmental load is reduced due to its long lifespan.
Weather resistant steels are used in various applications requiring high weather stress:
- facades
- bridges
- steel tanks
- sea containers
- chimneys
- fire places
- any other steel structure used outside
- Dimensions
- Welding
The most common weather resistant steel coil and plate thicknesses and sizes available in our stock:
| QUALITY | THICKNESS (mm) | WIDTHxLENGTH (mm) |
|---|---|---|
| Quarto plates S355J2WP / 1.8946 (COR-TEN B) | 3–50 | 2000 x 6000 |
| Coils S355J2WP / 1.8946 (COR-TEN B) | 0,6–20 | Coil width: 1000–2000 Sheet dimensions: 1500 x 3000 1500 x 6000 |
We supply weather resistant steels also in other dimensions. Call and ask us.
The welding properties of weather resistant steel are similar to that of unalloyed conventional structural steels.
During welding attention should be paid to prevention of the cold cracking behavior of the steel and the mechanical properties of the weld joint. The optimal working temperature and the cleanliness of the surfaces are both crucial. An effective mean to avoiding cold cracking is preheating. It delays the cooling of the weld region and thereby slows the hydrogen effusion.
Due to the alloying elements – which lead to higher Carbon Equivalent Values (CEV), the need for preheating starts a bit earlier with weather resistant steel than with conventional structural steels. Hot cracking may take place in the weld metal of phosphorous alloyed weather resistant steels.
Welding conditions have a crucial effect on mechanical properties of welding joints. Thermal effects of welding are not allowed to weaken the steel properties in the way the construction would not meet the requirements set. Mechanical properties should be achieved both welding metal and heat-affected-zone (HAZ).
