Key Features of Corten (or Cor-ten) Steel
All corten grades are weather-resistant, copper chromium alloy steels. They have a high level of resistance to atmospheric weathering, especially when compared to other unalloyed steels. Both Corten A and Corten B are aesthetically pleasing and have been used in a range of architectural applications such as sculptures and bridges.
Corten A Weathering Steel
Corten A is a blend of alloying copper, nickel, and chromium with added phosphorous. This blend of materials makes Corten A well-suited for gas flue applications. It is also frequently used for aesthetic fascias but is not recommended for applications that bear a heavy load.
Corten B Weathering Steel
Corten B is similar in composition to Corten A and is used for many structures due to its corrosion resistance. However, it is much more suitable for load-bearing structures than Corten A.
Difference Between Corten A and Corten B:
Chemical Composition:
Corten A:
Contains higher levels of phosphorus and is designed to oxidize in a relatively low sulfur environment.
Corten B:
Has a lower level of phosphorus compared to Corten A, making it suitable for applications requiring enhanced resistance to atmospheric corrosion.
|
Grade |
C |
Si |
Mn |
P |
S |
Al |
V |
Cu |
Cr |
Ni |
|
Corten A |
0.12 |
0.25/0.75 |
0.20/0.50 |
0.07/0.15 |
0.030 |
0.015/0.06 |
– |
0.25/0.55 |
0.50/1.25 |
0.65 |
|
Grade |
C |
Si |
Mn |
P |
S |
Al |
V |
Cu |
Cr |
Ni |
|
Corten B |
0.19 |
0.30/0.65 |
0.80/1.25 |
0.035 |
0.030 |
0.020/0.06 |
0.02/0.10 |
0.25/0.40 |
0.40/0.65 |
0.40 |
Tensile Strength:
Corten A:
Generally has higher tensile strength than Corten B.
Corten B:
Slightly lower tensile strength compared to Corten A.
The difference between Corten A mechanical properties and Corten B mechanical properties:
|
Grade |
Thickness (mm) |
Plate Products |
Yield Strength |
Tensile Strength |
Elongation |
|
Corten A |
2 – 12 |
6 – 12 |
345 |
485 |
20 |
|
Grade |
Thickness (mm) |
Plate Products |
Yield Strength |
Tensile Strength |
Elongation |
|
Corten B |
2 – 13 |
6 – 40 |
345 |
485 |
19 |
Weldability:
Corten A:
Requires pre-heating before welding to prevent cracking due to its higher phosphorus content.
Corten B:
Generally better weldability and can be welded without pre-heating under most conditions.
Applications:
Corten A:
Commonly used in architectural structures, bridges, facades, and outdoor sculptures where a weathered, rusty look is desired.
Corten B:
Often chosen for structural applications that require higher strength and enhanced resistance to atmospheric corrosion.
Weathering Characteristics:
Corten A:
Develops a stable rust-like appearance over time, which acts as a protective barrier against further corrosion.
Corten B:
Exhibits similar weathering characteristics to Corten A but may require slightly longer exposure to elements to achieve the desired patina.
Corrosion Resistance:
Corten A:
Offers good resistance to atmospheric corrosion.
Corten B:
Provides improved resistance to atmospheric corrosion compared to standard carbon steel.
Availability:
Both Corten A and Corten B are readily available in various forms such as sheets, plates, coils, and structural sections.
In summary, while Corten A and Corten B are both weathering steel grades designed to develop a protective rust-like patina, they differ in terms of chemical composition, tensile strength, weldability, and specific applications. Corten A is favored for its rust aesthetic and architectural applications, while Corten B is chosen for its enhanced strength and corrosion resistance in structural designs.
GNEE STEEL stocks both Corten A and Corten B weathering steel grades in a range of thicknesses and plate widths. We offer expert advice on which steel grade is best suited to your application, get in touch with the team today for more information.
