EN 10025-5 S235J2W is an economical, low-strength grade of weather-resistant structural steel. It balances moderate strength (yield strength ≥ 235 MPa, tensile strength typically 360 - 510 MPa), good low-temperature toughness(impact energy ≥ 27J at -20°C), excellent atmospheric corrosion resistance, good weldability, and favorable workability. Widely used in various outdoor steel structure projects, it is particularly suitable for applications requiring both weather resistance and low-temperature toughness. This steel is one of the preferred choices for designers working on outdoor structures that demand long service life, low maintenance, and a distinctive appearance.

Key Features and Advantages

1. Excellent Atmospheric Corrosion Resistance:

Its corrosion resistance is typically 4 to 6 times that of ordinary carbon structural steel, depending on the environment.

The stable rust layer formed on the surface (commonly known as "patina") prevents further penetration of rust into the material, achieving "rust resistance through rusting."

Key Advantages: Reduces or eliminates the need for painting maintenance, lowers lifecycle costs, and is highly suitable for exposed structures.

2. Good Mechanical Properties and Weldability:

Meets the strength (yield strength ≥ 235 MPa) and toughness (impact energy ≥ 27J at -20°C) requirements for structural steel.

While ensuring weather resistance, its chemical composition is optimized to provide good weldability, eliminating the need for complex preheating and post-weld treatments as required for certain high-strength steels (though proper welding procedures must still be followed).

3. Environmental and Aesthetic Value:

Reduces paint usage, making it more environmentally friendly and aligning with green building principles.

The unique reddish-brown rust layer appearance offers a distinctive industrial style for architectural and landscape design, often utilized by architects to achieve specific aesthetic effects.

Carbon Equivalent of S235J2W Weathering Steel Plate (Corten Steel Plate)

Carbon Equivalent: CEV ≤ 0.44%

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/low-maintenance" and "natural aesthetic" characteristics, S235J2W Weathering Steel Plate (Corten Steel Plate) is commonly used in structures exposed to atmospheric environments that are difficult or inconvenient to regularly paint and maintain:

1. Bridges: Trusses, guardrails, supports, etc., for railway bridges, highway bridges, and pedestrian bridges.

2. Building Facades and Structures: Support structures for building curtain walls, roofs, and decorative components.

3. Tower Structures: Components for transmission towers, communication towers, lighthouses, and wind turbine tower sections.

4. Transportation: Containers, railway freight carriages, and frames for engineering machinery.

5. Landscape Design: Outdoor sculptures and art installations.

6. Other Outdoor Facilities: Open-air pipeline supports, railings, noise barriers, outdoor billboard frames, etc.

Usage Precautions

1. Initial Rusting Stage: Before a stable protective layer forms (approximately 1-3 years, depending on the environment), rust runoff may occur, potentially contaminating surrounding concrete or walls. Drainage design or the installation of catch trays should be considered during planning.

2. Welding Material Compatibility: Specialized weathering steel electrodes/wires must be used during welding to ensure that the weld seam possesses corrosion resistance and mechanical properties matching those of the base metal.

3. Avoid Direct Contact: Direct contact with ordinary carbon steel or stainless steel should be avoided to prevent electrochemical corrosion. If contact is unavoidable, insulation treatment is required.

4. Unsuitable for Specific Environments: In high-salinity environments (such as coastal splash zones), persistently damp conditions, areas with severe industrial acid rain pollution, or environments containing high concentrations of chloride ions, its advantages may diminish. Careful assessment or additional protective measures are necessary.

Key Differences Between Similar Grades

International Standard Equivalence

* Since the requirements for chemical composition, mechanical properties, and corrosion resistance mechanisms vary slightly across different standards, "equivalence" typically refers to similarities in intended use and performance rather than exact identity.