CORTEN STEEL

Corten Steel Plate

Corten Steel / Cor-Ten Steel

 

What is Corten Steel or Cor-Ten Steel ?

Corten steel (often referred to as Cor–Ten) is a weather resistant steel which could more accurately be termed as an "Atmospheric Corrosion Resistant Steel".

It is a copper chromium alloy steel – this alloy displays a greater level of resistance to atmospheric weathering when compared to other unalloyed steels. It's chemical composition promotes the early formation of an adhering protective layer of rust when exposed to the elements.

The protective layer constantly develops and regenerates over time, reacting to the pollutants in the atmosphere. Consideration should be made with regard to the thicknesses used especially when the material is utilized for structural rather than solely cosmetic purposes.

The benefits of such a steel are immediately obvious – a self–protecting steel is economic, long lasting and easily recyclable. Presinox Impex are a stockiest of Corten–A and Corten–B.

When Corten is exposed to the atmosphere, it develops an initial layer of rust as ordinary steel does. But, as times goes by, this early product gradually converts to a fine-textured rust (protective rust) that tightly adheres to the base metal, providing a protective layer that protects the base metal and suppresses further corrosion.

The name COR-TEN refers to the two distinguishing properties of this type of steel: Corrosion resistance and Tensile strength.

The original COR-TEN received the standard designation A242 (COR-TEN A) from the ASTM International standards group. Newer ASTM grades are A588 (COR-TEN B) and A606 for thin sheet. All alloys are in common production and use.

 

ASTM Specifications

Weathering steels are a family of ASTM specifications, as well as several trademarked specifications exhibiting similar corrosion resistant properties. The ASTM specifications are A588, A242, A606-4, A847, A871-65 and A709-50W. The primary trademarked product is Cor-ten®.

ASTM A588

ASTM A588 is a high strength low-alloy structural steel specification with improved atmospheric corrosion resistance for structural steel shapes such as angles, channel and beams, as well as steel plate and bars. The A588 specification is intended primarily for use in welded bridges and other structures where savings in weight or added durability is important along with the longer life cycle due to its corrosion resistant properties.

The atmospheric corrosion resistance of A588 is substantially better than that of carbon steels such as A36 and A572-50 with or without copper addition. When properly designed and exposed to the atmosphere, A588 is suitable for many applications in the unpainted condition.

ASTM A588 has a 50ksi minimum yield strength and a 70ksi minimum tensile strength.

ASTM A242

ASTM A242 is a high strength low-alloy structural steel specification with improved atmospheric corrosion resistance. This specification is normally applicable to steel plates through one-half inch in thickness.
The atmospheric corrosion resistance of A242 is substantially better than that of carbon steels such as A36 and A572-50 with or without copper addition. When properly exposed to the atmosphere, A242 is suitable for many applications in the unpainted condition.

ASTM A242 has a 50ksi minimum yield strength and a 70ksi minimum tensile strength.

ASTM A606-4

ASTM A606-4 is a high strength, low alloy specification with improved atmospheric corrosion properties covering hot and cold rolled steel sheet, strip and coil intended for use in structural and miscellaneous purposes, where savings in weight and/or added durability is important. A606-4 contains additional alloying elements and provides a level of corrosion resistance substantially better than that of carbon steels with or without copper addition. When properly designed and exposed to the atmosphere, A606-4 can be used bare (unpainted) for many applications.

ASTM A606-4 has a 50ksi minimum yield strength and a 70ksi minimum tensile strength.

ASTM A847

ASTM A847 is a high strength low alloy steel covering cold-formed welded square and rectangular tubing and pipe. The atmospheric corrosion resistance of this steel in most environments is substantially better than carbon steel with or without copper addition. ASTM A847 is intended for welded, bolted or riveted construction of bridges and other structures where high strength and enhanced corrosion resistance are required. When properly designed and exposed to the atmosphere, A847 can be used bare (unpainted) for many applications.

ASTM A847 has a 50ksi minimum yield strength and a 70ksi minimum tensile strength.

ASTM A709-50W

ASTM A709-50W is a standard specification for structural steel in bridges. ASTM A709-50W covers high strength, low allow steel structural shapes, plates and bars. The atmospheric corrosion resistance of this steel in most environments is substantially better than carbon steel with or without copper addition. ASTM A709-50W shall have an atmospheric corrosion index of 6.00 or higher. When properly designed and exposed to the atmosphere, A709-50W is suitable for many applications in the bare (unpainted) condition.

ASTM A871-65

ASTM A871-65 is a high strength low-alloy structural steel plate with improved atmospheric corrosion resistance. This specification provides for a 65ksi minimum yield strength and an 80ksi minimum tensile strength plus the atmospheric corrosion resistance of this steel in most environments is substantially better than that of carbon steels with or without copper addition. When properly designed and exposed to the atmosphere, this steel can be used bare (unpainted) for many applications. The primary application for A871-65 is transmission and lighting poles as an aesthetically pleasing alternative to a galvanized structure.

ASTM A572-65

ASTM A572-65 is a high strength low-alloy columbium-vanadium structural steel. This specification provides for a 65ksi minimum yield strength and an 80ksi minimum tensile strength. The primary application for ASTM A572-65 is galvanized transmission and lighting poles. We purchase this grade with a limited .05Max Silicon content to facilitate the subsequent galvanizing process. ASTM A572-65 is supplied to meet a Charpy V-Notch test of 15ft/LB at -20F.

Cor-Ten®

Cor-Ten® is United States Steel Corporation (USS) trade name for an atmospheric corrosion resistant steel it developed to used where higher strength and longer life cycle material were desired. These steels naturally form a layer of rust or patina when exposed to various atmospheric conditions. This patina is what the guards this material against future corrosion. As Cor-Ten® became more popular over the years other producing mills began to develop their own atmospheric corrosion resistant steel. Therefore, ASTM steeped in a created what is considered equivalent specifications to Cor-Ten® in most applications. The applicable equivalent ASTM specifications are ASTM A588, A242, A606-4, A847 and A709-50W.

 

 

 Equivalent or Nearby Standard Specifications :

Steel Grade
TKS Standard	EN Standard	ASTM Standard	ASTM Standard	Material No.
COR-TEN A*	S355JOW	ASTM 588 GRADE A	ASTM A 242 TYPE 2	1.8946

 

 

Steel Grade
TKS Standard	EN Standard	ASTM Standard	ASTM Standard	Material No.
COR-TEN B*	S355JOW	ASTM 588 GRADE B	ASTM B 242 TYPE 2	1.8946

 

* Corten is a registered mark referenced here for informational purposes only. We are not related to Corten and provide Weathering Steel.