Marine aluminum equipment, ships has developed to light weight

The oxide film on aluminium and aluminium alloy has a great influence on its electrode potential. 4N aluminium in 5.3% NaCl + 0.3% H2O2 solution has a potential of -0.87 + 0.0lV to the glycol electrode, and all the factors that have an influence on the oxide film have an influence on the potential. Therefore, the oxide film in marine aluminum ship is of decisive importance for the corrosion resistance of aluminium and aluminium alloys: any factor that improves the denseness of the oxide film, increases the thickness of the oxide film and improves the insulating properties of the oxide film contributes to the corrosion resistance. For this reason, all aluminium materials used in the marine environment must undergo appropriate surface treatment.

The corrosion resistance of marine aluminium and aluminium alloys in seawater is listed in descending order as follows: aluminium-magnesium alloys (5xxx series), aluminium (1xxx series), aluminium-manganese alloys (3xxx series), aluminium-magnesium-silicon alloys (6xxx series), aluminium zinc-magnesium alloys (7xxx series), aluminium-silicon alloys (4xxx series), aluminium-zinc-copper-magnesium alloys (7xxx series), aluminium-copper-magnesium alloys (2xxx series) copper-magnesium alloys (2xxx series) and aluminium-copper alloys (2xxx series). Therefore, when choosing materials for marine structures, 5xxx series alloys should be preferred, and at the same time, the magnesium content of the alloy should be ≤ 5% in order to have good forming properties.

At present, marine aluminum ship is mainly used in small, light weight, high speed boats and other ship types, such as wave-piercing catamarans, high speed patrol boats, military auxiliary boats, business boats, etc. "Aluminium is the material of choice for designers of high-speed vessels such as fast ferries, hydrofoils, fishing boats, work boats and high-speed car ferries." "All-aluminium fast vessels such as wave-piercing catamarans, hydrofoils and multihulls are already reaching speeds of 35 to 50 knots, which has significantly changed waterway transport and saves half their sailing time compared to conventional vessels. In order to improve the range and sailing speed of ships, all will be built more often in marine aluminum ship in the future." From the aspect of environmental protection, ships in lakes and inland rivers are now facing gradually increasing pressure on environmental protection due to diesel leakage, and the development trend of their ship power is electric gradually replacing diesel power, so the demand for lighter ships in lakes and inland rivers will gradually rise; in terms of military ships, military ships using aluminium alloy can not only reduce the weight of the hull, but also achieve a lower centre of gravity and improve the stability of the ship's navigation In terms of military ships, the use of aluminium alloy in military ships can not only reduce the weight of the hull, but also achieve the purpose of lowering the centre of gravity and improving the navigation stability of the ship.