?Ship aluminum alloy can be divided into wrought aluminum alloy and cast aluminum alloy according to different manufacturing processes. Because marine aluminum alloy has special requirements for strength, corrosion resistance, weldability, etc., aluminum-magnesium alloys are mostly used for marine aluminum alloys. , Aluminum-magnesium-silicon alloys and aluminum-zinc-magnesium alloys, of which aluminum-magnesium alloys are widely used on ships. According to the company's product production situation, the following main focuses on the marine deformed aluminum alloy.
Characteristics and uses of ship aluminum alloy
Ship aluminum alloy can be divided into aluminum alloy for ship hull structure and aluminum alloy for outfitting. The aluminum alloy used for ship hull structure is mainly three alloys of 5083, 5086 and 5456. 6000 series alloys will crystallize in seawater. It is mainly used for the superstructure of ships. Outfitting aluminum alloy mainly uses extruded profiles. The strength and process performance of the 7000 series alloy after heat treatment is even better than that of the 5000 series alloy. It has broad application prospects in shipbuilding, mainly used in naval superstructures, such as extruded structures, armor plates, etc. However, the disadvantage of 7000 alloys is their poor stress corrosion resistance, which limits the application range of this series of alloys.
Selection principle of ship aluminum alloy
One is that it has a high specific strength and specific modulus. The structural strength and size of a ship are closely related to the yield strength and elastic modulus of the material. Since the elastic modulus and density of aluminum alloys are roughly the same, the addition of alloying elements has little effect. Therefore, increasing the yield strength within a certain range can reduce the ship The boat structure is strong. It is often difficult for high-strength aluminum alloys to have excellent corrosion resistance and weldability at the same time. Therefore, marine aluminum alloys are generally medium-strength, corrosion-resistant, and weldable alloys.
The second is an excellent welding performance. At present, the automatic argon arc welding method is mainly used in ships. Good weldability means that the tendency of cracks formed during welding of aluminum alloys is smaller, which means that aluminum alloys must have good welding crack resistance. Because under shipbuilding conditions, the lost welding performance cannot be restored by heat treatment again.
The third is excellent corrosion resistance. Ship structures are used in harsh seawater media and marine environments. Therefore, corrosion resistance is one of the main signs of marine alloys. The fourth is that aluminum alloy has a good cold and hot forming properties. Because the shipbuilding has to undergo multiple treatments of cold processing and hot processing, the marine aluminum alloy must be easy to process and shape without cracking defects, and it can still meet the strength and strength after processing. Corrosion resistance requirements.
Ship aluminum alloy materials are more stringent. Currently, aluminum alloy products such as 5083, 5086, 5454, 5754, and 6061 are mostly used. In practical applications, the advantages of marine aluminum alloys are very obvious. The first is the small specific gravity, which can reduce the weight of the ship, save energy, and increase the load. Secondly, it has good corrosion resistance, reduces the cost of oiling, and extends the service life. The third is the welding and processing formability number, which is conducive to later processing. Finally, aluminum scrap is easy to recycle and can be recycled. At the same time, it does not burn and is safe in a fire.
