Four material selection principles for aluminum alloys used on ships

Marine aluminum alloy is one of the emerging fields of aluminum alloy products, and it is also the key direction for the transformation and upgrading of many aluminum processing enterprises in China. Marine aluminum alloys are used in marine vessels and other fields, so they have more stringent process requirements and performance standards than other common aluminum alloy products.

The principle of selecting aluminum alloy for ships can be divided into four aspects. First, there is a high specific strength and specific modulus. The structural strength and size of the ship are closely related to the yield strength and elastic modulus of the material. Since the elastic modulus and density of the aluminum alloy are substantially the same, the addition of alloying elements has little effect. Therefore, increasing the yield strength within a certain range is effective for reducing the structure of the ship. High-strength aluminum alloys are often difficult to have both excellent corrosion resistance and weldability. Therefore, marine aluminum alloys are generally medium strength, corrosion resistant weldable alloys. The second is excellent welding performance. At present, the main method used in the ship is the automatic argon arc welding method. Good weldability means that the tendency of the aluminum alloy to form cracks during welding is small, that is, the aluminum alloy has good welding crack resistance. The lost weldability cannot be restored by reheating under shipbuilding conditions. The third is excellent corrosion resistance, the ship's structure is used in many harsh seawater media and marine environment. Therefore, corrosion resistance is one of the main signs of marine alloys. Fourth, the aluminum alloy has good cold and hot forming properties. Because the ship is manufactured by cold processing and hot processing, the marine aluminum alloy must be easy to process, no crack defects, and can still meet the strength and strength after processing. Corrosion resistance requirements.