1.Key Features
| Property | Technical Specification |
|---|---|
| Self-Protecting Patina | Forms a dense oxide layer (5–10× more protective than carbon steel; corrosion rate ≤0.01 mm/yr per ISO 9223) |
| Alloy Design | Cu-P-Cr-Ni system (e.g., 0.25–0.55% Cu, 0.30–1.25% Cr) enhances corrosion resistance |
| Mechanical Strength | Yield strength: 345–690 MPa (varies by grade) |
| Weldability | Requires low-hydrogen processes (e.g., SMAW with E7018-W electrodes) |
2. Chemical Composition (Typical %)
| Grade | C (max) | Mn | P | S (max) | Si | Cu | Cr | Ni |
|---|---|---|---|---|---|---|---|---|
| ASTM A588 | 0.19 | 0.80–1.25 | 0.04 max | 0.05 | 0.15–0.40 | 0.20–0.40 | 0.40–0.65 | 0.25 max |
| S355J0WP | 0.16 | 0.50–1.50 | 0.06–0.15 | 0.030 | 0.25–0.75 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
3. Applications
Bridges: Unpainted structural components (e.g., A709 Gr50W for U.S. bridges)
Architecture: Facades, sculptures (e.g., Chicago's Cloud Gate)
Transportation: Shipping containers, railway cars
Industrial: Chimneys, transmission towers
4. Processing Guidelines
Cutting: Plasma/laser cutting recommended to minimize HAZ
Welding: Use weathering-grade filler metals (e.g., AWS E7018-W)
Forming: Cold bending radius ≥3× plate thickness
5. Patina Development Stages
Initial (0–6 months): Orange-brown surface
Intermediate (6–18 months): Darker, uneven texture
Mature (2+ years): Dense, dark brown protective layer
6. Global Standards Cross-Reference
| Region | Standard | Equivalent Grades |
|---|---|---|
| Americas | ASTM A588/A606 | A242 (Type 2), A709 Gr50W |
| Europe | EN 10025-5 | S355J0WP (≈A588), S355J2WP (higher toughness) |
| Asia | JIS G3114 | SMA400AW (≈A588), SMA490AW |
7. Ordering Parameters
Thickness: 2–150 mm
Width: 1,000–3,500 mm
Surface: Mill scale, shot-blasted, or pre-weathered
Certification: EN 10204 3.1, ASTM A6/A20
