Galvalume® Steel Coil / Sheet / Plate (AZ/Al-Zn Coated)

Q: Q1. Why Galvalume outperforms galvanized in cut-edge corrosion?

A: Zn-rich zones in the eutectic structure sacrificially protect exposed edges with <0.5mm creep after 2,000 hrs salt spray (ASTM A857).

Q: Q2. Recommended seam sealing for roofing applications?

A: 1) Silicone sealant (ASTM C920) or 2) Huaxiao’s proprietary Zn-Mg edge coat – withstands 10% joint movement.

Q: Q3. Can Galvalume be spot-welded to galvanized steel?

A: Yes – with 30% higher force to overcome Al oxide. Use dome electrodes + post-weld sealant to prevent galvanic corrosion.

Q: Q4. Painting preparation protocol?

A: 1) Alkaline clean → 2) Zirconium nano-conversion coating → 3) Epoxy primer → 4) PVDF/SMP topcoat.

Q: Q5. MOQ for custom AZ115 coating?

A: 12 MT with ±4g/m² tolerance (ASTM A792 Class II).

Q: Q6. Warranty for architectural applications?

A: 30-year substrate warranty (certified to AAMA 203-12).

Huaxiao-Alloy’s Galvalume® (55% Al-43.4% Zn-1.6% Si) delivers triple-defense corrosion resistance – combining aluminum’s barrier protection, zinc’s sacrificial cathodic action, and silicon’s alloy-layer control. Engineered for 3-6x longer service life versus galvanized steel in roofing, HVAC, and automotive applications.

1. PRODUCT SPECIFICATIONS & TOLERANCES

Form	Thickness	Width	Coating Class	Surface Finish
Coil	0.18–3.00 mm (±0.03mm)	600–1,600 mm (±0.5mm)	AZ60/AZ90/AZ150	Minimized spangle (M), Regular spangle (R)
Sheet	0.30–4.50 mm (±0.05mm)	900–2,200 mm (±1mm)	AZ75/AZ135	Skin-passed (S), Anti-fingerprint (AF)
Plate	2.30–20.0 mm (±0.4%)	1,200–3,500 mm	AZ120	Blasted/Coated (BC), Oiled

Coating Mass Reference (ASTM A792):

AZ60: 60 g/m² total (≈18µm)
AZ150: 150 g/m² total (≈45µm)

2. BASE MATERIAL ENGINEERING

Optimized Steel Grades for Structural & Forming Performance

Grade	Standard	Yield (MPa)	Tensile (MPa)	Typical Applications
S250GD+AZ	EN 10346	250–330	330–440	Roofing, wall cladding
HCT600XD+AZ	EN 10346	550–680	600–750	Solar tracker frames
ASTM A653 SS550 AZ	ASTM A653	550 min	600 min	Automotive chassis parts
JSC490W+AZ	JIS G 3321	490 min	510–640	Warehouse shelves

3. GALVALUME® COATING TECHNOLOGY

Microstructure & Protective Mechanism

Coating Composition: 55% Al, 43.4% Zn, 1.6% Si
Alloy Layer Structure:
- Top Layer: 80% Al-rich dendrites → forms Al₂O₃ barrier
- Interlayer: Zn-rich eutectic → sacrificial protection
- Substrate Bond: FeAl₃/Fe₂Al₅Si inhibition layer (<1µm)
Self-Healing: Zn migrates to scratches via electrochemical potential

Performance Benchmarks

Test	Huaxiao AZ90	HDG (Z180)	Pure Aluminum Coating
Salt Spray (ASTM B117)	1,200 hrs	250 hrs	600 hrs
Cyclic Corrosion (SAE J2334)	200 cycles (rust-free)	60 cycles	100 cycles
Solar Reflectivity	75%	28%	82%
Max Continuous Temp	340°C	200°C	480°C

4. MECHANICAL & PHYSICAL PROPERTIES

Property	Test Method	AZ90 (0.7mm)	AZ150 (1.2mm)
Yield Strength	ASTM E8/E8M	320 MPa	400 MPa
Fatigue Limit (10⁷ cycles)	ISO 1143	280 MPa	350 MPa
Thermal Conductivity	ASTM E1461	50 W/m·K	48 W/m·K
Coefficient of Friction	ASTM D1894	0.10 (AF finish)	0.14 (M finish)
Cut-Edge Creep (500h salt spray)	EN 13523-10	0.2 mm	0.1 mm

5. INDUSTRY-SPECIFIC APPLICATIONS

Sector	Critical Component	Huaxiao Solution	Certification
Building & Construction	Standing seam roofs	AZ135 Coil (S finish)	FM Global 4471, UL 90
HVAC & Ductwork	Air handling unit panels	AZ90 Sheet (AF finish)	SMACNA HVAC Duct Std.
Renewable Energy	Solar mounting structures	AZ150 Plate	AS/NZS 1170.2 Wind Load
Automotive	Trailer underbody shields	AZ120 Sheet	GMW16232-M Steel Grade