Zinc Coated Steel, Aluminum-Zinc Alloy Coated Steel, and Zinc-Aluminum-Magnesium Coated Steel are three popular coated steel products sold by Wanzhi Group. They are widely used in the fields of building and structure, transportation, appliance manufacturing, home appliance manufacturing, energy and environmental protection due to their excellent corrosion resistance, durability and stability in harsh environments.
Product Description
Galvanized steel is the most cost-effective steel solution for conventional corrosion protection; Aluminum-zinc alloy steel with added aluminum enhances the steel’s heat reflectivity and UV resistance; Zinc-aluminum-magnesium coated steel is the ultimate in protection against extreme environments and is the preferred choice for high-investment steel solutions.
Galvanized Steel (Zinc Coated Steel)
- Coating process: Pure zinc is applied to the steel surface by means of a hot dip/electro-galvanizing process.
- Advantages: lowest cost, proven process (hot dip/electroplating), good processability, easy to weld.
- Disadvantages: zinc layer is easy to wear, high temperature (>200℃) failure, easy to corrode in the cut.
- International standard: ASTM A653), EN 10346.
- Scenario: building enclosure, home appliance shell, general industrial parts.
- Innovation: Chrome-free passivation + Nano-coating to enhance environmental friendliness.
Aluminum-zinc Alloy Coated Steel (Galvalume as representative)
- Coating process: Coated with an alloy of approx. 55% aluminum, 43.4% zinc and 1.6% silicon.
- Advantages: Excellent heat resistance, resistant to acidic environments, resistant to high temperatures and salt spray.
- Disadvantages: Cutting edges susceptible to galvanic coupling corrosion (sealing treatment required).
- Certification: ASTM A792, JIS G3321.
- Scenarios: Coastal architecture, automobile exhaust pipes, photovoltaic bezels.
- Innovation: Photocatalytic coating to expand environmental applications.
Zinc Aluminum Magnesium Coated Steel (ZAM Coating)
- Coating process: Coating is a mixture of zinc, aluminum and magnesium.
- Advantages: strong self-healing, resistant to red rust, long life in extreme environments.
- Disadvantages: High cost, welding requires specialized processes.
- Standard: EN 10346 (DX56D+ZM), JIS G3323.
- Scenarios: Offshore engineering, chemical equipment, high humidity appliances.
- Innovations: High magnesium alloy + superhydrophobic surface technology.
Performance comparison
| Performance Indicator | Galvanized Steel (GI/EG) | Galvalume (Zinc-Aluminum Coating) | Zinc-Aluminum-Magnesium Coating (ZAM) |
|---|---|---|---|
| Coating Composition | Zn≥99% | 55% Al – 43.4% Zn – 1.6% Si | Zn – 6% Al – 3% Mg |
| Corrosion Mechanism | Sacrificial anode + physical barrier | Aluminum passivation film + sacrificial zinc | Self-healing oxide film (Mg aids repair) |
| Salt Spray Life | 500~3000 hours | 1500~6000 hours | 3000~6000+ hours |
| High Temperature Resistance | ≤200°C | ≤315°C | ≤300°C |
| Formability | Easy to punch, bend, and form | Higher hardness, processing cost higher than galvanized steel | Coating harder, processing more difficult |
| Surface Finish | Zero spangle, regular spangle, large/small spangle | Dense and uniform zinc crystal pattern | Dense, no zinc flower |
| Cost | Low | Medium | High |
Solution
| Application Field | Galvanized Steel (HDG/EG) | Galvalume (Zinc-Aluminum Coating) | Zinc-Aluminum-Magnesium Coating (ZAM) |
|---|---|---|---|
| Construction & Structures | Roofs, fences, temporary barriers, light steel keels (general environment) | Coastal building roofs, high-temperature factories (salt spray/high temperature resistance) | Coastal building roofs, offshore platforms, chemical factories (extreme corrosion environments) |
| Transportation | Truck cabins, general vehicle frames | Car exhaust pipes, train carriages (high temperature resistance), new energy vehicle battery boxes | Car chassis, ship decks (impact resistance + salt spray resistance) |
| Home Appliance Manufacturing | Washing machine shells, air conditioner brackets | Oven liners, water heater shells (high temperature resistance) | High humidity appliance components (antibacterial requirements) |
| Industrial Equipment | Ventilation ducts, shelves | Chimneys, industrial furnace exteriors (high temperature resistance) | Mining machinery, chemical pipelines (abrasion + corrosion resistance) |
| Energy & Environmental Protection | Solar panel supports (low cost) | Photovoltaic frames (lightweight + weather resistance) | Offshore wind power structures (self-healing + corrosion resistance) |
Certification Standards
| Standard Type | Galvanized Steel (GI/EG) | Galvalume (Zinc-Aluminum Coating) | Zinc-Aluminum-Magnesium Coating (ZAM) |
|---|---|---|---|
| International Standards | ASTM A653, EN 10346 | ASTM A792, JIS G3321, EN 10346 | JIS G3323 |
| Environmental Certification | RoHS/REACH | RoHS/REACH (Low VOC coatings) | RoHS/REACH (No heavy metal leaching) |
| Industry Certification | GB/T 2518 | AAMA 2605 | ISO 9227 |
| Fire Protection Certification | EN 13501-1 (Class B) | EN 13501-1 (Class A2) | EN 13501-1 (Class A1 Non-flammable) |
Deep Processing Technology Comparison
| Process/Material | GI (Galvanized Steel) | Galvalume (Aluzinc Steel) | ZAM (Zinc-Aluminum-Magnesium Steel) |
|---|---|---|---|
| Stamping | Suitable for shallow stamping (elongation ≥ 20%) | Deep drawing requires special coating (e.g., SMP) | Recommended high elongation substrate (DX56D+Z) |
| Bending | – Minimum bending radius: 1T (T = plate thickness)
– Springback compensation: 2°~5° – Surface prone to pressure marks |
– Minimum bending radius: 1.5T
– Springback compensation: 5°~8° – High coating hardness, needs scratch protection |
– Minimum bending radius: 2T
– Springback compensation: 8°~12° – Magnesium increases brittleness, requires progressive bending |
| Welding | Resistance welding | Laser welding works well | Recommended laser or friction welding |
| Cutting | Laser cutting | Water jet cutting | Laser cutting |
| Surface Treatment | – Chromate passivation / Chromium-free zirconium treatment
– Coating (PPGI) |
– Chemical conversion film
– Coating (PPGL) – Can be anodized |
– Closed coating
– Self-healing coating |
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