S355J2WP Weather Resistant Steel to EN 10155-1993
S355J2WP Weather Resistant Steel to EN 10155-1993 - Composition, Properties & Equivalents
Comprehensive technical data for EN 10155-1993 S355J2WP weather resistant steel coil: chemical composition, mechanical and physical properties, international equivalents, and application guidance.
Hot rolling, cold forming, welding, cutting, bending
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
S355J2WP Weather Resistant Steel to EN 10155-1993 Introduction
S355J2WP is a structural steel with enhanced atmospheric corrosion resistance, classified as a weathering steel under the former European standard EN 10155-1993. By adding controlled amounts of alloying elements—primarily copper, chromium, and phosphorus—the steel forms a dense, adherent oxide layer (patina) when exposed to the weather, which protects the base metal and often eliminates the need for painting. The designation 'S355' indicates a minimum yield strength of 355 MPa for thicknesses up to 16 mm, while 'J2' guarantees Charpy impact toughness of at least 27 J at -20°C. 'W' stands for weathering, and 'P' denotes the purposeful addition of phosphorus in the range 0.06–0.15% to further improve corrosion resistance.
Key attributes:
- Excellent atmospheric corrosion resistance – suitable for unpainted use in many environments
- Good weldability using standard methods with appropriate consumables
- Impact toughness down to -20°C for structural reliability
- Wide range of applications in bridges, building envelopes, containers, and railway vehicles
- Available as hot-rolled coils, plates, and sections
S355J2WP Weather Resistant Steel to EN 10155-1993 Chemical Composition
The chemical requirements specified in EN 10155-1993 for grade S355J2WP. Phosphorus is intentionally alloyed in the range 0.06–0.15% to boost atmospheric corrosion resistance. Copper and chromium contents are also controlled. Residual elements should not exceed customary levels; unless otherwise agreed, the steel may contain small amounts of niobium, vanadium, titanium, or nickel as grain-refining elements.
| Element | Standard Value (weight %) | Remarks |
|---|---|---|
| Carbon (C) | ≤ 0.12 | For thickness ≤ 16 mm; for greater thicknesses max. 0.15 may be agreed |
| Silicon (Si) | ≤ 0.75 | Higher values permitted if balanced by deoxidation practice |
| Manganese (Mn) | ≤ 1.00 | Slightly higher Mn up to 1.30 may be allowed for thick products |
| Phosphorus (P) | 0.06 – 0.15 | Key element for weather resistance |
| Sulfur (S) | ≤ 0.035 | Low sulfur ensures good toughness and weldability |
| Chromium (Cr) | 0.30 – 1.25 | Contributes to protective patina |
| Copper (Cu) | 0.25 – 0.55 | Essential for stable oxide layer formation |
| Nickel (Ni) | ≤ 0.65 | Optional addition; improves toughness and resistance in marine environments |
| Molybdenum (Mo) | ≤ 0.30 | Residual or intentional microalloying |
| Nitrogen (N) | ≤ 0.009 | For aluminum-killed steel with fine grain practice |
| Aluminum (Al) total | ≥ 0.020 | For fine grain; free Al may be specified |
S355J2WP Weather Resistant Steel to EN 10155-1993 Physical Properties
The following physical constants are typical for low-alloy weathering steel at room temperature and for design purposes. They are not mandated by EN 10155 but are widely used in engineering calculations. Slight variations may occur depending on exact composition and manufacturing process.
| Property | Typical Value | Unit | Temperature / Condition |
|---|---|---|---|
| Density (ρ) | 7.85 | g/cm³ | 20 °C |
| Modulus of elasticity (E) | 210 | GPa | 20 °C |
| Shear modulus (G) | 80 | GPa | 20 °C |
| Poisson's ratio (ν) | 0.3 | – | 20 °C |
| Thermal expansion coefficient (α) | 11.1 × 10⁻⁶ | /K | 20 – 100 °C |
| Thermal expansion coefficient (α) | 12.1 × 10⁻⁶ | /K | 20 – 200 °C |
| Thermal expansion coefficient (α) | 12.9 × 10⁻⁶ | /K | 20 – 400 °C |
| Thermal conductivity (λ) | 42 | W/(m·K) | 100 °C |
| Thermal conductivity (λ) | 38 | W/(m·K) | 200 °C |
| Specific heat capacity (Cp) | 460 | J/(kg·K) | 20 °C |
| Electrical resistivity (ρe) | 0.16 × 10⁻⁶ | Ω·m | 20 °C |
S355J2WP Weather Resistant Steel to EN 10155-1993 Mechanical Properties
Tensile and impact properties for hot-rolled products according to EN 10155-1993. The values are valid for transverse test pieces unless longitudinal testing is agreed. For impact toughness, longitudinal Charpy V-notch specimens at -20°C shall give a minimum of 27 J. Bending requirements are not explicitly tabulated in the standard but typically a mandrel diameter of 2t (for t ≤ 16 mm) and 3t (for t > 16–100 mm) is applicable for 180° cold bending without cracking.
| Property | Standard Value | Unit | Test Conditions |
|---|---|---|---|
| Yield strength (ReH) | ≥ 355 | MPa | Thickness ≤ 16 mm |
| Yield strength (ReH) | ≥ 345 | MPa | Thickness 16 – 40 mm |
| Yield strength (ReH) | ≥ 335 | MPa | Thickness 40 – 63 mm |
| Yield strength (ReH) | ≥ 325 | MPa | Thickness 63 – 80 mm |
| Yield strength (ReH) | ≥ 315 | MPa | Thickness 80 – 100 mm |
| Tensile strength (Rm) | 470 – 630 | MPa | Thickness ≤ 100 mm |
| Elongation (A5) | ≥ 22 | % | Thickness ≤ 40 mm, L0=5.65√S0 |
| Elongation (A5) | ≥ 21 | % | Thickness 40 – 63 mm |
| Elongation (A5) | ≥ 20 | % | Thickness 63 – 100 mm |
| Charpy impact energy (KV) | ≥ 27 | J | -20°C, longitudinal, average of 3 specimens |
| Bending angle | 180° | deg | Mandrel dia. = 2t (t ≤ 16 mm), 3t (t > 16–100 mm) – general guidance |
S355J2WP Weather Resistant Steel to EN 10155-1993 Fully Equivalent Material Standards and Replaceable Grades
| Country/Region | Standard | Grade | Remarks |
|---|---|---|---|
| Europe | EN 10155-1993 (withdrawn) | S355J2WP | Original standard; still used for reference |
| Europe | EN 10025-5:2019 | S355J2WP | Current European standard for hot-rolled weather resistant steel |
| International | ISO 4952:2003 | Fe 355 W (J2W grade) | Comparable weathering steel; specify impact class J2 |
| China | GB/T 4171-2008 | Q355GNH | Chemical composition very close; ensure -20°C impact requirement is agreed (J2 level) |
| Japan | JIS G 3114:2008 | SMA490AW (J2 equivalent) | Similar yield and weathering resistance; impact test condition must be confirmed |
| USA | ASTM A588/A588M | Grade B | Closest US weathering steel; slightly higher C and Mn; corrosion resistance comparable |
S355J2WP Weather Resistant Steel to EN 10155-1993 Application Introduction
S355J2WP is designed for structural applications where extended service life and reduced maintenance are desired. The self-protecting patina develops in alternate wet-dry cycles typical of outdoor exposure, making it ideal for unpainted bridges, architectural cladding, and open industrial structures. It is not recommended for permanently damp, buried, or submerged conditions unless special precautions are taken. Typical fabrication processes include cutting, cold forming, and all common arc welding methods (MAG, SAW, MMA) using matching or slightly over-alloyed welding consumables.
Key industries and product examples:
Product Applications: Weathering steel bridges (pedestrian, road, rail), Facade panels and rainscreens, Railway wagons and locomotive frames, Corrugated roofing and siding sheets, Container corrugated walls and frames, High-voltage transmission towers, Street furniture and sculptures, Flue-gas ducting and chimneys
Processed into products: Bridge girders, box sections, and stiffeners, Pre-fabricated building columns and beams, Wagon side panels and underframes, Weld-free folded profiles and cassettes, Plates, flanges, and webs in fabricated beams, Laser-cut architectural panels and louvers, Tower leg members and bracing angles
Application industries: Civil Engineering and Bridge Construction, Building and Architecture, Railway and Rolling Stock, Shipping and Container Manufacturing, Power Transmission and Telecommunication Towers, Industrial Structures and Heavy Equipment
S355J2WP Weather Resistant Steel to EN 10155-1993 Similar or Nearly Equivalent Alternative Materials
| Country/Region | Standard | Grade | Remarks |
|---|---|---|---|
| Europe | EN 10025-5 | S355J2W | Same strength and toughness, but phosphorus is ≤0.035% (not intentionally added); slightly lower corrosion resistance |
| USA | ASTM A588/A588M | Grade A | Weathering steel with min. 345 MPa yield; higher carbon and manganese, but equivalent in many structural uses |
| Japan | JIS G 3114 | SMA490BW | Modified phosphorus version; properties can be aligned by specification |
| China | GB/T 4171 | Q355GNHL | Low-phosphorus variant of Q355GNH; for applications requiring stricter cold formability |
| UK (former) | BS 4360 | WR 50 B / WR 50 C | Withdrawn British standard grades; equivalent to S355J2WP in chemical composition |
Notes:
Welding: When welding S355J2WP, use low-hydrogen consumables designed for weathering steel (e.g., AWS A5.29 E81T1-W H8 or equivalent) to ensure the weld metal develops a similar patina and has adequate toughness at -20°C. Preheat and interpass temperature control may be required for thick sections according to the carbon equivalent (CEV typically ≤0.52).
Durability: The protective oxide layer matures after several months of outdoor exposure; accelerated weathering may be achieved by wet/dry cycling. In marine atmospheres with high chloride deposition, periodic washing or a higher nickel content (>0.5%) improves performance.
Forming: Cold bending radii should be at least 2.0t for transverse bends and 2.5t for longitudinal bends when thickness ≤ 16 mm, in line with EN 10155 and good practice.
Compliance: Since EN 10155 was withdrawn, orders and certifications should refer to EN 10025-5:2019. Ensure that impact testing is specified at -20°C to meet J2 requirements.
- Share
