EN 10025-5 S355J2W is a cost-effective, weldable weathering structural steel, commonly referred to as "weathering steel" or "Corten steel."

Its core characteristic is that, when exposed to the atmosphere, it forms a dense and adherent protective rust layer ("Patina") on its surface. This layer effectively slows down further corrosion, providing corrosion resistance that is 4 to 6 times greater than that of ordinary carbon steel in most atmospheric environments.

Its key advantages are "corrosion resistance + high strength + low maintenance," making it particularly suitable for structural components intended for long-term outdoor use. It significantly reduces painting and maintenance costs while meeting toughness requirements in low-temperature environments.

It is an ideal material choice for modern architectural design, bridge engineering, and outdoor structures that prioritize long service life, low maintenance, and distinctive aesthetic effects. When selecting this material, it is essential to ensure it meets the standard requirements of the project location and to follow proper processing and installation guidelines.

Key Features and Advantages

1. Excellent Atmospheric Corrosion Resistance: This is its most prominent feature. The addition of small amounts of alloying elements such as copper, chromium, and nickel promotes the formation of a stable rust layer on the surface.

2. High Strength: Yield strength ≥355 MPa, tensile strength between 470–630 MPa, offering excellent load-bearing capacity.

3. Good Low-Temperature Toughness: Meets impact energy requirements at -20°C (≥27 J), making it suitable for outdoor structures in low-temperature service environments.

4. Weldability: The chemical composition of the steel is optimized for good weldability. However, it generally requires the use of compatible dedicated welding materials and may need to follow specific Welding Procedure Specifications (WPS).

5. Paint-Free or Reduced Maintenance: In many application scenarios, it can be used without painting, allowing natural rusting to form a protective layer, thereby significantly reducing lifecycle maintenance costs. It can also be painted to provide longer-lasting protection.

Carbon Equivalent of S355J2W Weathering Steel Plate (Corten Steel Plate)

Carbon Equivalent: CEV ≤ 0.52%

Calculate using the International Institute of Welding (IIW) formula: CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

Due to its maintenance-free nature, high strength, and unique appearance, S355J2W Weathering Steel Plate (Corten Steel Plate) is widely used in building and engineering structures exposed to the atmosphere:

1. Architectural structures: Exposed steel structures of large public buildings (such as stadiums, art galleries, railway stations, airport terminals), bridges, transmission towers, roofs, and curtain wall support structures.

2. Bridge engineering: Particularly suitable for landscape bridges, pedestrian bridges, highway bridges, and railway bridges, reducing lifecycle maintenance costs and construction disruptions.

3. Tower structures: Power transmission towers, communication towers, wind turbine towers (non-rotating components, such as tower platforms).

4. Sculptures and art installations: Many modern sculptures and public artworks utilize its rust-colored appearance as a design element.

5. Containers and railway freight vehicles: Used in the manufacturing of transportation equipment with high durability requirements.

6. Other outdoor structures: Such as lighting poles, railings, noise barriers, scaffolding, etc.

Usage Precautions

1. Initial Rusting Stage: Before a stable protective rust layer forms (which typically takes about 1–3 years, depending on the environment), rust runoff from the steel surface may contaminate surrounding concrete or walls. Design considerations should include drainage or protective measures.

2. Unsuitable for Specific Environments: In continuously damp environments, areas with chloride ions (e.g., coastal salt spray, de-icing salts), or high sulfur dioxide levels (e.g., severe industrial pollution), the corrosion resistance advantage may diminish, and uneven corrosion may even occur. Evaluation or additional protective measures are required.

3. Welding and Processing: Although it has good weldability, appropriate welding materials (typically those matching the weathering resistance of the base material) and suitable welding techniques must be selected during welding to maintain the corrosion resistance and mechanical properties of the weld area.

4. Surface Treatment: To accelerate the formation of a stable rust layer, "rust stabilizers" (also known as "rust promoters") can be used.

Key Differences Between Similar Grades

International Standard Equivalence

* Equivalent materials are only approximations, mechanical properties and chemical composition must be compared during application design.