When comparing lightweight steel keels, one must consider the differences in scratch resistance and durability between galvanized and aluminium-zinc plated steel.
Differences Between Galvanized and Aluminium-Zinc Plating:
Galvanized Steel:
- Coating and Usage: Galvanized light steel coatings vary based on their intended environment and required corrosion resistance. The zinc coating can range from 120g/m² to 275g/m².
- Designation: For example, Z275 refers to galvanized steel with a total zinc coating weight of 275g/m² on both sides.
- Physical Changes: Over time, galvanized steel exposed to the elements will react with oxygen, causing the surface to blacken.
Aluminium-Zinc Plated Steel (Galvalume):
- Corrosion Resistance: Aluminium-zinc plated steel offers superior corrosion resistance, three times that of pure galvanized steel. This is due to the formation of a dense aluminium oxide layer that prevents further corrosion.
- Aesthetics: It features attractive zinc flowers on the surface, making it suitable for use as building exterior panels.
- Designation: AZ150 is a common abbreviation for aluminium-zinc plated steel, indicating a specific coating weight.
- Durability: The aluminium component provides excellent protection against chemical corrosion and physical reactions, maintaining the keel's appearance and preventing rust over time.
- Field Testing: Aluminium-zinc plated steel has undergone over 20 years of outdoor exposure tests in various atmospheric conditions, proving its superior edge protection compared to galvanized steel.
Heat Reflectivity:
- Aluminium-zinc plated steel has twice the thermal reflectivity of galvanized steel, making it an excellent thermal insulator. This property enhances its suitability for applications where heat reflection is beneficial.
In summary, aluminium-zinc plated steel, or Galvalume, offers enhanced corrosion resistance, better aesthetic longevity, and superior thermal reflectivity compared to traditional galvanized steel, making it a more durable and versatile choice for various applications.
Aluminium-zinc coated steel coils undergo various surface treatments to enhance their performance and suitability for different applications. Here are some common surface treatments:
1. Chromate Treatment:
- Description: A chemical treatment involving the application of chromate compounds.
- Purpose: Enhances corrosion resistance and provides a good base for subsequent painting or coating.
2. Oiling:
- Description: A thin layer of oil is applied to the surface.
- Purpose: Prevents oxidation and corrosion during storage and transport. It also aids in processing by reducing friction.
3. Passivation:
- Description: A chemical process that forms a protective oxide layer on the surface.
- Purpose: Increases corrosion resistance and extends the life of the steel by preventing surface rust.
4. Anti-fingerprint Coating:
- Description: A special coating that resists fingerprint marks.
- Purpose: Keeps the surface clean and aesthetically pleasing, particularly useful in appliances and electronics.
5. Resin Coating:
- Description: A thin layer of resin is applied to the surface.
- Purpose: Enhances the surface's resistance to scratches and corrosion, and provides a good base for painting.
6. Phosphate Treatment:
- Description: A chemical treatment that applies a phosphate layer.
- Purpose: Improves paint adhesion and enhances corrosion resistance.
7. Pre-painting (Coil Coating):
- Description: The steel is coated with paint or other coatings.
- Purpose: Provides immediate protection and aesthetic appeal, eliminating the need for additional painting after installation.
These surface treatments ensure that aluminium-zinc coated steel coils offer superior performance, longevity, and versatility in various industrial applications.
Category |
Details |
---|---|
Thickness Range | 0.14 mm - 2.00 mm |
Width Range | 600 mm - 1500 mm |
Coil Weight | Up to 25 tons |
Coil Inner Diameter | 508 mm / 610 mm |
Coating Composition | 55% Aluminum, 43.4% Zinc, 1.6% Silicon |
Coating Weight | AZ50 - AZ200 (50 g/m² - 200 g/m²) |
Surface Finish | Regular Spangle, Mini Spangle, Zero Spangle |
Surface Treatment | Chromated, Non-Chromated, Oiled, Dry, Anti-fingerprint |
Mechanical Properties | |
- Yield Strength | 300 - 550 MPa |
- Tensile Strength | 300 - 600 MPa |
- Elongation | 10% - 30% (depending on grade) |
Spangle | Regular, Minimised, Zero |
Coil Length | Custom lengths based on customer requirements |
Standard Compliance | ASTM A792, JIS G3321, EN 10346 |
Applications | Roofing, Siding, HVAC, Appliances, Automotive, Agricultural Equipment, Industrial Components |
1. Construction:
- Roofing and wall panels
- Gutters and downspouts
- Steel framing and structural supports
- Siding and cladding materials
2. Automotive:
- Body panels
- Underbody components
- Heat shields and exhaust systems
3. Appliances:
- Housings for washing machines, dryers, and refrigerators
- Microwave oven panels and components
4. Agricultural Equipment:
- Silos and grain bins
- Farm machinery and equipment panels
5. Industrial:
- Air conditioning and heating ducts
- Electrical cabinets and enclosures
- Furniture and storage systems
Summary:
55% Aluzinc steel coils are a versatile and durable material known for their superior corrosion resistance, heat resistance, and aesthetic appeal. These coils are used in various industries, including construction, automotive, appliances, agriculture, and industrial applications, providing long-lasting performance and protection.
When exporting aluminized zinc-coated steel coils, the packaging is crucial to ensure the material arrives in good condition. The packaging generally follows these steps:
1. Inner Packaging:
- Plastic or VCI (Volatile Corrosion Inhibitor) Paper: The coil is first wrapped in plastic or VCI paper to protect against moisture and corrosion during transit.
- Waterproof Paper: A layer of waterproof paper is often added over the VCI paper for additional moisture protection.
2. Outer Packaging:
- Metal Strapping: Several metal straps are used to secure the coil tightly. These straps are often made of steel to provide the necessary strength.
- Edge Protectors: Edge protectors are placed at the coil edges where the metal strapping is applied to prevent damage during handling.
- Steel or Aluminum Cover: An outer layer of steel or aluminum is wrapped around the coil for impact resistance.
- Palletization: If required, the coil can be placed on a wooden or steel pallet. This makes it easier to handle with forklifts and other lifting equipment.
3. Markings and Labeling:
- Identification Labels: Each coil is labeled with relevant information such as grade, weight, dimensions, and destination.
- Export Markings: The package might also include export-specific markings, such as handling instructions, port of discharge, and consignee details.
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