Corten steel tubes, also known as weathering steel tubes, are hollow sections made from Corten steel. Corten steel is a group of steel alloys that are designed to form a rust-like appearance when exposed to weathering, creating a protective layer against further corrosion. Corten steel tubes are used in various structural and architectural applications due to their unique aesthetic appeal and weather-resistant properties. Corten A is a weather resistant steel created by alloying copper, chromium and nickel. In addition to this, Corten A has added phosphorous which makes the material best suited for gas flue applications and for aesthetic facias. However, it is not advisable to use Corten A in heavy load-bearing scenarios; in such cases, Corten B or S355J2W would be more appropriate choices.

The typical chemical composition of Corten-A (09CuPCrNi-A) steel includes:

- C: 0.12% - 0.21%

- Si: 0.25% - 0.75%

- Mn: 0.2% - 0.5%

- P: 0.07% - 0.15%

- S: 0.030% max

- Cu: 0.25% - 0.55%

- Ni: 0.12% - 0.65%

- Cr: 0.50% - 1.25%

- Other elements: 0.06% max (each), 0.12% max (total)

The mechanical properties of Corten-A (09CuPCrNi-A) steel are generally:

- Yield Strength: 345 MPa

- Tensile Strength: 480 MPa

- Elongation: 22%

- Charpy V-notch Impact Test: 20 J (-20°C)

- China: 09CuPCrNi-A

- USA: ASTM A242/A588

- Japan: JIS G3125

- Germany: DIN 1.8946

- France: NF A 35-502

- United Kingdom: BS 4360

1. Corrosion Resistance: Corten-A steel tube forms a stable rust-like appearance, which acts as a protective layer against atmospheric corrosion. This natural oxidation process eliminates the need for additional protective coatings.

2. Aesthetic Appeal: The unique rust-colored appearance gives Corten-A a distinctive and aesthetically pleasing look, making it popular for architectural and artistic applications.

3. Low Maintenance: Due to its ability to develop a protective layer, Corten-A requires minimal maintenance compared to traditional steels.

4. Durability: The steel has good strength and durability, making it suitable for various structural applications in challenging environmental conditions.

5. High Strength: Corten-A has good mechanical properties, including high tensile strength, making it suitable for structural applications.

Corten-A (09CuPCrNi-A) steel finds applications in various industries and structures, including:

1. Architectural Structures: Corten-A steel is often used in the construction of architectural elements such as building facades, bridges, and outdoor sculptures.

2. Outdoor Furniture: Its unique appearance makes Corten-A an attractive choice for outdoor furniture and decorative items.

3. Container Manufacturing: Corten-A is used in the manufacturing of shipping containers due to its corrosion resistance.

4. Railway Rolling Stock: It is employed in the construction of railway wagons and containers.

5. Transmission Poles: Corten-A steel tube is utilized in the fabrication of transmission poles for its durability and weathering properties.

6. Landscaping: The weathered appearance of Corten-A is popular in landscaping for garden edging, retaining walls, and other outdoor features.

Welding Corten-A steel requires attention to ensure the weld area retains corrosion resistance. Specific welding electrodes, such as E7018 or E8018-W, may be recommended, and post-weld treatments may be necessary to restore the protective layer. Welding on steel that is corten is relatively as similar as low carbon steel. The only precaution the welders need to take is regarding the filler or electrode which is different from mild steel. When it comes to choosing a welding electrode for weathering steel, AWS E7018 is most suitable. The choice of electrode depends on two factors - required strength and code requirements.

Corten steel has been the most widely-used metal for decades owing to its look and benefits. It overcomes rust, which is the major drawback associated with steel. The necessary expertise and experience in welding already exist. Hence, welders should be able to use it without any hassles.

Corten Steel Tube