Marine aluminum alloys types、characteristics and uses

Types, characteristics, uses, etc. of marine aluminum alloys

Marine aluminum alloys can be divided into deformed aluminum alloys and cast aluminum alloys according to different manufacturing processes. Since marine aluminum alloys have special requirements for strength, corrosion resistance, weldability, etc., marine aluminum alloys are mostly aluminum-magnesium alloys, aluminum-magnesium-silicon alloys and aluminum-zinc-magnesium alloys. Among them, aluminum-magnesium alloys are the most widely used on ships. According to the company’s product production situation, the following mainly focuses on marine deformed aluminum alloys.

Marine aluminum alloys

Characteristics, uses and chemical composition of marine aluminum alloys

Ship aluminum alloys can be divided into aluminum alloys for hull structure and aluminum alloys for outfitting according to their uses. The aluminum alloys used in the hull structure are mainly 5083, 5086 and 5456. Since 6000 series alloys will undergo intergranular corrosion in seawater, they are mainly used in the upper structure of ships. Outfitting aluminum alloys are mainly extruded profiles. The strength and process performance of 7000 series alloys after heat treatment are superior to those of 5000 series alloys. They have broad application prospects in shipbuilding and are mainly used in ship superstructures, such as extruded structures and armor plates. However, the disadvantage of 7000 alloy is its poor stress corrosion resistance, which limits the scope of use of this series of alloys.

Types and examples of uses of marine aluminum alloys

Marine aluminum alloys can be divided into plates, profiles, tubes, bars, forgings, and castings according to product types. The company’s current aluminum alloy product types are mainly plates and strips.

Note:

1. 5052 alloy is also used for outfitting, and the varieties include plates, tubes and rods.

2. 5083, 5086 and 6N01 alloys can produce wide thin-walled extruded profiles.

3. The thickness of the plate is determined by the hull structure, ship specifications and the use location. From the perspective of hull lightweighting, thin plates are generally used as much as possible, but the depth of plate corrosion during use should also be considered. The plates commonly used are thin plates above 1.6mm and thick plates above 30mm. In order to reduce welding, 2.0m wide aluminum plates are often used, and large ships use 2.5m wide aluminum plates. The length is generally 6m. Some special specifications of plates are also used according to the shipyard contract. For anti-skid, the deck uses patterned plates.

Marine aluminum alloys

State of marine aluminum alloys

The state of aluminum alloys indicates the material processing method, internal structure and mechanical properties. Generally, engineers use materials in different states according to different uses. The 5000 series alloys used in hull structures use O and H states, and the 6000 series alloys use T state. The H state details of the 5000 series alloys and the state codes of the 6000 series alloys and AC series casting alloys listed in the Japanese JIS standard are shown in the following table.