Weather Resistant Steel

 

Weather Resistant Steel

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.

Atmospheric corrosion resistant steel is used for large on- and offshore structures including bridges. It contains elements such as Cu, Cr and Ni for improved weathering and corrosion resistance. Some of its applications need painting while others don’t. Those used for the latter have thin and robust, anti-corrosive films on the surface that are formed through reaction with air.

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

Steel grades

KS : SMA355AW/AP/BW/BP/CW/CP, HSB380W/460W

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JIS : SMA490AW/AP/BW/BP/CW/CP

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ASTM : A588 Gr A/B