AZ55 Galvalume Steel Coil: Premium 55% Al-Zn Coating for Extreme Weather Resistance
AZ55 Galvanized Steel Coil Product Overview
AZ55 Galvanized Steel Coil is a hot-dip aluminum-zinc alloy-coated steel engineered for demanding environments. With a 55% aluminum, 43.5% zinc, and 1.5% silicon composition, it offers 3–6x longer corrosion resistance compared to traditional galvanized steel. Ideal for roofing, automotive parts, and industrial equipment, its dual-phase coating (Al-rich skeleton + Zn-Al eutectic) provides self-healing edge protection and a lifespan exceeding 25 years in coastal or high-humidity regions. Compliant with ASTM A792, EN 10346, and JIS G3321, it combines versatility with sustainability through recyclable materials and RoHS-certified finishes.
Key Technical Specifications
1. Dimensional & Coating Properties
- Thickness: 0.12–6.00 mm (±5% tolerance per ASTM A924)
- Width: 600–1,500 mm (custom slitting for HVAC, automotive panels)
- Coating Weight: 30–185 g/m² (8–45 μm thickness)
- Standard Grade: 50 g/m² (13.3 μm) for roofing
- Heavy-Duty Grade: 150 g/m² (37.5 μm) for offshore applications
2. Chemical Composition
| Element | Al (%) | Zn (%) | Si (%) | Fe (%) | Trace Elements (max) |
|---|---|---|---|---|---|
| Content | 55–58 | 41–43 | 1.5–2 | ≤0.25 | Pb:0.05, Cr:0.05, Ni:0.05 |
Coating Advantages:
- Thermal Reflectivity: 80% (vs. 20% for galvanized steel), reducing rooftop temperatures by 10–15°C.
- Salt Spray Resistance: 1,500–3,000 hours (ASTM B117) without red rust.
Mechanical Performance
| Grade (EN 10346) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Hardness (HV) |
|---|---|---|---|---|
| DX51D+AZ | 240–380 | 270–500 | ≥22 | 85–125 |
| S350GD+AZ | ≥350 | ≥420 | ≥16 | 120–160 |
| S550GD+AZ | ≥550 | ≥550 | – | 180–220 |
Performance Metrics:
- Bendability: 0T–2T (180° bend at 0.5 mm thickness).
- Weldability: 8–12 kA spot welding current (20% lower than galvanized steel).
- Punching Force: ≤50 kN for 2 mm sheets.
Surface Treatment Options
| Coating Type | Coating Weight | Surface Finish | Applications |
|---|---|---|---|
| Zero Spangle (Z) | 50–150 g/m² | Smooth, reflective | Architectural façades, solar panels |
| Minimized Spangle (M) | 30–100 g/m² | Matte, low glare | Automotive interiors, appliances |
| Anti-Fingerprint (N5) | 75–185 g/m² | Chromate-free, textured | Electronics, medical equipment |
Environmental Certifications:
- RoHS Compliance: Chromium-free passivation (EN 10346-C5).
- GreenGuard Gold: Low VOC emissions for indoor use.
Applications
| Industry | Use Case | Recommended Grade |
|---|---|---|
| Construction | Standing-seam roofs | DX53D+AZ (150 g/m² coating) |
| Automotive | Exhaust systems, fuel tanks | S550GD+AZ (100 g/m² coating) |
| Agriculture | Livestock roofing, grain silos | S250GD+AZ (75 g/m² coating) |
| Energy | Solar panel backing, ducts | DX51D+AZ (50 g/m² coating) |
Global Standard Equivalents
| China (GB) | Europe (EN) | USA (ASTM) | Japan (JIS) |
|---|---|---|---|
| DC51D+AZ | DX51D+AZ | CS Type B | SGCC |
| S350GD+AZ | S350GD+AZ | SS345 | SGLC490 |
| S550GD+AZ | S550GD+AZ | SS550 | SGLC570 |
Sustainability & Compliance
- Recycled Content: ≥30% (ISO 14021-certified).
- Carbon Footprint: ≤1.2 tons CO2 per ton of steel.
- Certifications: LEED v4.1, ISO 9001, API 5L.
Packing And Delivery
