Here's a concise yet comprehensive overview of S355J0WP steel, including its chemical composition and key properties:
S355J0WP Steel (EN 10025-5:2019)
Classification: Weathering structural steel (similar to Corten B) with enhanced atmospheric corrosion resistance due to protective patina formation.
1. Chemical Composition (Weight %)
| Element | Min (%) | Max (%) | Role |
|---|---|---|---|
| C (Carbon) | - | 0.16 | Strengthening |
| Si (Silicon) | 0.25 | 0.75 | Deoxidation |
| Mn (Manganese) | 0.80 | 1.25 | Strength & Toughness |
| P (Phosphorus) | - | 0.030 | Corrosion Resistance |
| S (Sulfur) | - | 0.030 | Impurity Control |
| Cu (Copper) | 0.25 | 0.55 | Key for weathering resistance |
| Cr (Chromium) | 0.40 | 0.80 | Corrosion Stability |
| Ni (Nickel) | - | 0.65 | Low-T Toughness |
| Others (V, Ti) | Optional | ≤0.10 | Grain Refinement |
Notes:
Cu + Cr + Ni ≥ 0.50% for effective patina formation.
Low S/P improves weldability and ductility.
2. Key Properties
Yield Strength (ReH): ≥ 355 MPa
Tensile Strength (Rm): 470–630 MPa
Elongation (A₅): ≥ 20%
Impact Toughness: 27 J at 0°C (Charpy V-notch, J0 grade)
Corrosion Resistance: 2–4× better than carbon steel in rural/urban atmospheres.
3. Comparison to Similar Steels
| Grade | Standard | Key Difference vs. S355J0WP |
|---|---|---|
| S355J2WP | EN 10025-5 | Higher impact toughness (-20°C) |
| ASTM A588 | ASTM | Similar weathering performance (US equivalent) |
| S355J0W | EN 10025-5 | Lower Cu/Cr (weaker corrosion resistance) |
4. Typical Applications
Bridges, facades, transmission towers, and shipping containers.
