EN10025-5 S355J2WP Weathering Steel
EN10025-5 S355J2WP Weathering Steel: Superior Atmospheric Corrosion Resistance & Mechanical Properties
In-depth material data for S355J2WP weather-resistant structural steel per EN10025-5, including chemical composition, mechanical and physical properties, international equivalents, and applications.
Hot Rolling, Normalizing, Welding, Cutting, Bending, Cold Forming
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
EN10025-5 S355J2WP Weathering Steel Introduction
EN10025-5 S355J2WP is a structural weathering steel grade renowned for its improved atmospheric corrosion resistance. As part of the EN 10025-5 standard, this phosphorus-alloyed steel develops a protective oxide layer (patina) when exposed to the environment, which significantly reduces the need for painting and maintenance compared to conventional carbon steel. With a minimum yield strength of 355 MPa and a guaranteed Charpy impact energy of 27 Joules at -20°C (J2), it offers excellent structural integrity and toughness for low-temperature applications. Its key characteristic is the self-protecting patina, making it ideal for unpainted applications like bridges, facades, and sculptures. The material is delivered in a normalized or normalized rolled condition, ensuring fine-grained structure and consistent mechanical properties.
EN10025-5 S355J2WP Weathering Steel Chemical Composition of S355J2WP
The chemical composition of S355J2WP per EN 10025-5:2019 is designated to ensure both weathering resistance and mechanical properties. The key alloying elements are Phosphorus (P) (0.06-0.15%) and Chromium (Cr), Copper (Cu), and Nickel (Ni), which synergistically form the dense, adherent protective patina. Carbon content is controlled for weldability, while Manganese provides strength. The low temperature toughness is achieved by the fine-grain practice.
| Element | Standard Value (Max/Range, %) | Remarks |
|---|---|---|
| Carbon (C) | ≤ 0.12 | Maximum value |
| Silicon (Si) | ≤ 0.50 | Maximum value |
| Manganese (Mn) | 0.50 - 1.50 | Range |
| Phosphorus (P) | 0.06 - 0.15 | Key element for weathering resistance |
| Sulfur (S) | ≤ 0.030 | Maximum value |
| Chromium (Cr) | 0.40 - 0.80 | Enhances patina formation |
| Copper (Cu) | 0.25 - 0.55 | Enhances patina formation |
| Nickel (Ni) | ≤ 0.65 | Contributes to toughness and resistance |
| Molybdenum (Mo) | ≤ 0.10 | Maximum residual value |
| Nitrogen (N) | ≤ 0.012 | Maximum value for fine-grain grades |
| Aluminium (Al) | ≥ 0.020 | Used for grain refinement and deoxidation |
EN10025-5 S355J2WP Weathering Steel Physical and Thermal Properties of S355J2WP
The physical properties are not mandatory deliverables per EN 10025-5 but are typical values for design purposes. The alloying elements slightly alter properties like thermal expansion and thermal conductivity compared to pure iron. Density is comparable to other carbon steels. These values are valid for ambient temperature unless a temperature range is specified.
| Property | Typical Value | Unit | Test Condition / Temperature |
|---|---|---|---|
| Density (ρ) | 7.85 | kg/dm³ | at 20 °C |
| Modulus of Elasticity (E) | 210 | GPa | at 20 °C |
| Shear Modulus (G) | 81 | GPa | at 20 °C |
| Poisson's Ratio (ν) | 0.3 | — | at 20 °C |
| Thermal Expansion Coefficient (α) | 12.0 | 10⁻⁶/K | at 20 - 100 °C |
| Thermal Expansion Coefficient (α) | 12.5 | 10⁻⁶/K | at 20 - 200 °C |
| Thermal Expansion Coefficient (α) | 13.0 | 10⁻⁶/K | at 20 - 300 °C |
| Thermal Conductivity (λ) | 40 - 45 | W/(m·K) | along the lamellar plane, at 20 °C |
| Specific Heat Capacity (cp) | 460 - 480 | J/(kg·K) | at 20 - 100 °C |
| Electrical Resistivity (ρ_e) | 0.20 - 0.25 | Ω·mm²/m | at 20 °C |
EN10025-5 S355J2WP Weathering Steel Mechanical Properties of S355J2WP at Ambient Temperature
These mechanical properties are mandatory as per EN 10025-5 for products in the normalized (+N) delivery condition. The yield strength and tensile strength values vary with product thickness. The toughness, verified by the Charpy V-notch impact test, is guaranteed at a temperature of -20°C, designated by the 'J2' classification. Formability is validated via the mandrel diameter bending test.
| Property | Standard Requirement Value | Unit | Test Condition / Thickness Range |
|---|---|---|---|
| Yield Strength (ReH) | ≥ 355 | MPa | Nominal thickness ≤ 16 mm |
| Yield Strength (ReH) | ≥ 345 | MPa | Nominal thickness 16 - 40 mm |
| Tensile Strength (Rm) | 470 - 630 | MPa | Nominal thickness ≤ 16 mm |
| Tensile Strength (Rm) | 470 - 630 | MPa | Nominal thickness 16 - 40 mm |
| Elongation (A) | ≥ 22 | % | Longitudinal, L₀ = 80 mm for t < 3 mm |
| Elongation (A) | ≥ 20 | % | Longitudinal, L₀ = 5.65√S₀ for t ≥ 3 mm and ≤ 40 mm |
| Charpy Impact Energy (KV₂) | ≥ 27 | J | Longitudinal, TC = -20 °C |
| Bend Test (Mandrel Diameter) | No cracks | — | 180° Bending; a ≥ 150 for t ≤ 16 mm (a: thickness) for d=1a |
EN10025-5 S355J2WP Weathering Steel Exact Direct Equivalent Material Standards and Designations
| Country / Region | Standard | Designation (Grade) | Remarks |
|---|---|---|---|
| European Union | EN 10025-5 | S355J2WP | The original and defining standard. |
| International | ISO 4952 | S355WP | Closely equivalent, no direct J2 impact designation; verify toughness. |
| Japan | JIS G 3114 | SMA490BW | Very close match; B-suffix implies -5°C or higher, check manufacturer for -20°C toughness. |
EN10025-5 S355J2WP Weathering Steel Application Introduction
S355J2WP is selected for applications where a balance of structural strength, low-temperature toughness, and long-term corrosion resistance is required, often in an unpainted state. Its suitability is dependent on the specific environmental corrosivity category (C1-C3 as per ISO 9223) and design details to prevent water accumulation.
Product Applications: Unpainted Weathering Steel Bridges, Architectural Cladding and Facade Panels, Street Furniture and Sculptures, Welded Structural Beams and Columns, Highway Guardrails and Sound Barriers, Bulk Cargo and Intermodal Shipping Containers (Corten Boxes)
Processed into products: Bridge Girders, Box Girders, and Trusses, Welded Plate Girders, Internal and External Load-Bearing Frames, Bent and Formed Channel Sections, Base Plates and Connection Brackets, Durable Casings for Outdoor Machinery
Application industries: Civil and Structural Engineering, Bridge Construction, Architecture and Construction, Railway Rolling Stock, Energy (Transmission Towers), Port and Marine Infrastructure (non-immersed), Shipping Container Manufacturing
EN10025-5 S355J2WP Weathering Steel Near Equivalent and Substitute Material Grades
| Country / Region | Standard | Designation (Grade) | Key Difference Analysis |
|---|---|---|---|
| United States | ASTM A588 / A709 | Grade A / 50W | Similar yield (345 MPa min) and weathering concept. P content is not as tightly controlled in the same band; check toughness at low temperatures. |
| China | GB/T 4171 | Q355GNHD | Chinese weathering steel with similar mechanical profile. Chemical composition ranges, especially for P, differ; requires re-qualification for EU standards. |
| European Union | EN 10025-5 | S355J2W+N | Same strength and toughness class, but this grade relies more on Cr and Cu and less on P for its weathering resistance. |
Notes:
Welding considerations: S355J2WP requires specific welding consumables matching the weathering steel composition to ensure the weld zone also develops a protective patina. AWS A5.5 E7018-W1 or equivalent is commonly used. Patina formation requires alternating wet/dry cycles; it does not develop uniformly in continuously dry or submerged conditions. During weathering process, initial runoff may stain adjacent surfaces, requiring design measures to manage drainage. For thicknesses greater than 40mm, property values must be agreed upon at the time of order.
- Share
