Hot Dip Galvalume Steel Coil: Superior Corrosion Resistance for Construction & Industrial Applications
Hot Dip Galvanized Steel Coil Product Overview
Hot Dip Galvalume Steel Coil is a 55% aluminum-zinc alloy-coated steel (55% Al, 43.5% Zn, 1.5% Si) designed for extreme weather resistance. With a 30–185 g/m² coating weight (equivalent to 8–45μm thickness), it outperforms traditional galvanized steel by 2–4x in salt spray tests (1,500–3,000 hours vs. 720 hours). Ideal for roofing, automotive parts, and appliances, it combines self-healing切口 protection with a lifespan exceeding 25 years in coastal environments. Compliant with ASTM A792, EN 10346, and JIS G3321, it offers zero-spangle, anti-fingerprint, and chromate-free surface options.
Key Technical Specifications
1. Dimensional & Coating Properties
- Thickness: 0.12–6.00mm (±5% tolerance per ASTM A924)
- Width: 600–1,500mm (custom slitting for HVAC ducts)
- Coating Types:
- AZ (Al-Zn): 50g/m² (13.3μm) standard for roofing
- ZM (Minimized Spangle): Ra ≤0.8μm for high-gloss appliances
- AM (Anti-Fingerprint): SiO₂ nano-coating (≤0.01g/m² residue)
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 Advantage:
- Phase Structure: Dual-phase Al-rich skeleton + Zn-Al eutectic for synergistic anti-corrosion
- Thermal Reflectivity: 80% (vs. 20% for galvanized steel) reducing rooftop temps by 10–15°C
Mechanical Performance
| Grade (EN 10346) | Yield (MPa) | Tensile (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 @ 0.5mm thickness)
- Punching Force: ≤50kN for 2mm AZ-coated sheets
- Weldability: 8–12 kA spot welding current (20% lower than galvanized)
Corrosion Resistance & Durability
- Salt Spray Performance:
- Red Rust Threshold:
- 50g/m² coating: 1,200 hours (ASTM B117)
- 150g/m² coating: 3,000 hours (ISO 9227)
- Cut-Edge Protection: Zn-rich phase sacrificially corrodes at 0.02mm/year
- Red Rust Threshold:
- Thermal Stability:
- Continuous Service Temp: -50°C to 315°C
- Heat Reflectance: 75% @ 800nm wavelength (ASTM E903)
- Aesthetic Options:
- Spangle Control:
- Zero Spangle (Z): PVDF-painted for architectural façades
- Minimized Spangle (M): 8–12μm roughness for adhesion-critical parts
- Spangle Control:
Applications
| Industry | Use Case | Recommended Grade |
|---|---|---|
| Construction | Standing-seam roofs (25-year warranty) | DX53D+AZ 150g/m² |
| Automotive | Mufflers (900°C exhaust resistance) | S550GD+AZ |
| Appliances | Refrigerator liners (anti-bacterial AM coating) | DX54D+AZ |
Global Standard Equivalents
| China (GB) | Europe (EN) | USA (ASTM) | Japan (JIS) |
|---|---|---|---|
| DC51D+AZ | DX51D+AZ | CS Type B | SGCC |
| S350GD+AZ | S350GD+AZ | A653 SS345 | SGLC490 |
| S550GD+AZ | S550GD+AZ | A653 SS550 | SGLC570 |
Sustainability & Certifications
- Recycled Content: ≥30% (verified per ISO 14021)
- RoHS Compliance: Cr⁶+-free passivation (EN 10346-C5)
- Certifications: LEED v4.1, GreenGuard Gold (low VOC)
Packing And Delivery
