Aluminum Pipe and Groove for Boat Building
In the shipbuilding industry, aluminum tubes and aluminum groove have become an ideal choice to replace traditional steel due to their light weight, high strength and excellent corrosion resistance.
Aluminum pipes
1. Multiple applications of aluminum pipe
The "blood vessels" of the power system
The aluminum tubes of the hydraulic system (such as 5052 alloy) are responsible for transmitting high-pressure fluids. The smoothness of their inner walls can ensure that the flow efficiency of hydraulic oil is increased by more than 15%. The cryogenic pipelines of LNG carriers use 6061-T6 aluminum tubes, which can still maintain good toughness at -165℃.
The "skeleton" of the hull structure
6082-T6 aluminum tubes are often used to manufacture masts and supporting structures. Their tensile strength can reach more than 300MPa, which is 40% lighter than steel of the same specification. The superstructure of a certain type of frigate uses a 5083 aluminum pipe welded structure, which reduces the overall weight by 200 tons and increases the speed by 2 knots.
The "veins" of life support
The fresh water delivery system uses 3003 aluminum tubes, which have a chloride ion corrosion resistance that is 3 times higher than that of stainless steel, and the maintenance cycle is extended to 5 years. The fire-fighting pipeline uses 5454 aluminum tubes, and the pitting rate in a salt spray environment is only 0.01mm/year.
2. Performance of core alloys
The Cr element (0.15-0.35%) of 5052 alloy forms a dense oxide film, which makes its corrosion rate in seawater with a pH of 4-9 less than 0.05mm/year.
The T6 heat treatment (solid solution + aging) of 6061-T6 makes the precipitated phase evenly distributed, and the yield strength is increased by 200% compared with the annealed state.
The Mg content of 5083 alloy is optimized to 4.5%, and with the ultrapure water quenching process, the strength loss of the welding heat affected zone is controlled within 15%.
Aluminum groove parameters
Cross-section type: U-type (such as 50×25×3mm), C-type (such as 80×40×4mm), Ω-type (such as 100×50×5mm).
Forming process: Extrusion forming straightness ≤1mm/m, minimum bending radius 3 times wall thickness.
Connection method: TIG welding with 5356 welding wire, weld strength coefficient ≥0.95.
Certification system:
Marine aluminum tubes must be certified by Classification Societies like ABS. Groove aluminium must comply with ISO 1184-1 standards, and its fatigue life must be no crack extension under 10⁶ cycles.
Selection and Maintenance Guide
Environmental Adaptation Rule
Offshore vessels prefer 5052 alloy, which has a seawater corrosion resistance 2.3 times higher than 3003 alloy.
Polar ships recommend 6061-T6 aluminum tubes, which have an impact toughness of 28J at -60°C, which is better than carbon steel of the same specification.
Cost Optimization Strategy
The cost of 5052 aluminum tubes is 35% lower than that of 7075, and is suitable for non-load-bearing structures; while the unit strength cost of 7075-T6 in high-stress components is only 60% of that of stainless steel.
The modular design of customized groove aluminium can reduce the number of welds by 30% and the installation cost by 18%.
Original Source:https://www.marinealu.com/a/aluminum-pipe-and-groove-for-boat-building.html
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