Warship structures are often used in harsh seawater media and marine environment, so whether aluminum alloy is corrosion resistant or not is one of the main signs to determine whether it can be used as marine aluminum alloy. Generally, marine aluminum alloy matrix and welded joints are required to have no tendency of stress corrosion, exfoliation corrosion and intergranular corrosion in seawater and marine environment, and contact corrosion, crevice corrosion and marine biological adhesion corrosion should be avoided as far as possible. Small uniform corrosion and pitting corrosion are allowed.
Experience has shown that any kind of aluminum small boat can be used for decades without any obvious corrosion. The decommissioning of such ships is usually due to the outdated technology rather than the aging of the aluminum structure. Generally speaking, 5-series and 6-series aluminum-magnesium alloys have been recognized for their excellent resistance to marine climate, especially sea water erosion. Among them, 5083 aluminum plate is a typical welding aluminum alloy, which has the highest strength, weldability, corrosion resistance and low temperature performance among the non-heat treated alloys, so it can be used as a marine aluminum plate on the ship side.
At present, the 5083 aluminum sheet of zhongxin Aluminum has entered the world shipbuilding market. Because of its low density and high strength, the side of the ship made with it can reduce the ship weight by more than 20%.
