The aluminum for marine use are mainly 5000 series and 6000 series series aluminum alloys. Among them, 5083 aluminum alloy has become the first choice for hull structure due to its excellent comprehensive performance, 6061 aluminum alloy is suitable for superstructure.
Commonly used aluminum alloy types of aluminum for marine use:
1. 5000 series marine grade aluminum alloy (aluminum-magnesium series)
- Features: good corrosion resistance, high strength, strong weldability, it is the most commonly used alloy series in shipbuilding.
- Common grades:
5083: Has high strength and good corrosion resistance, widely used in the manufacture of hull structures such as decks, bulkheads, ribs, etc.
5086: Has good ductility and corrosion resistance, and is often used in the manufacture of ship tops and shipboards.
5754: This alloy has good processability and welding performance, and is often used in ship side and bottom outer plates, etc.
5454, 5052: It is the main material for manufacturing decks, with excellent seawater corrosion resistance.
2. 6000 series aluminum alloy (aluminum-magnesium-silicon series)
- Features: easy to process, good corrosion resistance, suitable for ship superstructures and decorative parts.
- Common grades:
6063: Commonly used in porthole profiles in ship superstructures, as well as masts, gangways and other parts.
6061: Has high bending strength and ductility, suitable for manufacturing cantilevers, bridges and other parts.
The most suitable aluminum alloy for boat building:
5083-H116 is the most widely used and best comprehensive aluminum alloy in shipbuilding for the following reasons:
- Corrosion resistance: magnesium elements form a dense oxide film, which is more than 5 times more resistant to seawater corrosion than carbon steel, and is especially suitable for long-term immersion environments.
- Lightweight and strength: The density is only 1/3 of that of steel, but the strength is close, which significantly reduces the weight of the hull and improves the speed and fuel efficiency.
- Welding performance: excellent arc welding performance, not easy to deform after welding, suitable for complex hull structures.
- Low maintenance cost: surface damage can be restored by simple repair (such as repair welding), and the service life is more than 30 years.
- Standardization support: H116 state is certified by classification societies to ensure quality.
Selection in special scenarios
- Ultra-low temperature environment (such as LNG ships): 5059 or 5086 aluminum alloys, which still maintain ductility at -162°C.
- High-load components: 7000 series alloys (such as 7A05) can be used in combination with anti-corrosion coatings, but strict protection is required.
5083-H116 is the best aluminum for marine use, taking into account corrosion resistance, strength and lightweight; 5059 aluminum can be used for high-end scenarios (such as LNG transportation). Other aluminum alloys (such as 5052, 5454) are used for secondary components according to specific needs.
