ASTM A709/S355J0W Carbon Steel Coil: Bridge-Grade Steel with Enhanced Weathering Resistance
Product Overview
ASTM A709/S355J0W carbon steel coil is a high-strength low-alloy (HSLA) structural steel compliant with ASTM A709, EN 10025-2 S355J0W, and JIS G3114 SMA570W. Designed for bridges, shipyards, and railway components, this steel delivers 250–690 MPa yield strength and 16–23% elongation while offering 6.0+ atmospheric corrosion index for unpainted outdoor use. Available in Grades 36, 50, 50W, and HPS70W, it combines hot/cold rolling precision with quenched & tempered durability for critical infrastructure.
Key Technical Specifications
1. Production & Dimensions
- Process:
- Hot-rolled: 2.75–100mm (±1.2% tolerance)
- Cold-rolled: 0.2–3mm (±0.5% tolerance)
- Width: 45–2,200mm (compatible with automated bridge girder lines)
- Surface: Self-passivating patina (Grade 50W) or laminated film (anti-UV)
2. Chemical Composition
| Grade | Thickness | C (≤) | Mn | Cu (≥) | Cr | V |
|---|---|---|---|---|---|---|
| 50W | ≤100mm | 0.19% | 0.80–1.25% | 0.25% | 0.40–0.65% | 0.02–0.10% |
| HPS70W | ≤65mm | 0.15% | 0.85–1.35% | 0.25% | 0.30–0.50% | 0.01–0.10% |
Trace elements: P ≤0.04%, S ≤0.05%, Ni ≤0.50%
Mechanical Properties
| Grade | Thickness (mm) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|---|
| 36 | ≤100 | 250 | 400–550 | 20 |
| 50W | ≤100 | 345 | 485 | 18 |
| HPS70W | ≤65 | 485 | 585–760 | 19 |
Tested per ASTM A370 (longitudinal specimens)
Performance Advantages
- Weathering Resistance:
- Corrosion index: 6.0+ (vs. 4.2 for standard carbon steel).
- Salt spray resistance: 2,000+ hours without coating (ASTM B117).
- Structural Integrity:
- Fatigue strength: 210 MPa at 2 million cycles (Grade 50W, 25mm thickness).
- Bend radius: 3× thickness (ASTM A6/A6M compliant).
- Weldability:
- Carbon Equivalent (CEV): 0.38–0.45 (IIW formula).
- Preheating: Not required below 32mm (AWS D1.5 bridge code).
- Low-Temperature Toughness:
- Charpy V-notch: 34J at -40°C (Grade HPS70W, 20mm).
Applications by Grade
| Grade | Industry | Use Case |
|---|---|---|
| 50W | Civil Eng. | Highway bridge decks |
| HPS70W | Offshore | Oil rig support structures |
| 36 | Rail | Freight car underframes |
Global Equivalents
| ASTM A709 | EN 10025 | JIS G3114 | GB/T 1591 |
|---|---|---|---|
| 50W | S355J0W | SMA570W | Q355NH |
| HPS70W | S460ML | – | Q460GNH |
Sustainability & Compliance
- Recycled Content: 87% (mill-certified)
- RoHS Compliance: Lead <0.008%, Chromium VI-free
- Certifications: AISC, CE Mark EN 1090-2
Packing And Delivery
