Causes of corrosion of marine aluminum plates

I believe that many people must have such questions, the current aluminum plate due to the use of requirements is complex and changeable, and aluminum plate must undergo strict process treatment, why is there still marine aluminum plates can not avoid corrosion?

1. Metallurgical reasons

The metallurgical causes of aluminum plate corrosion are mainly affected by processing, heat gold stress and casting, cathodic polarization increases the stress corrosion of aluminum plate, and the stress corrosion of stirred welding is also lower than that of fusion welding. The aluminum plate of 04 has been properly treated, and such an aluminum plate is less prone to corrosion. The type of aluminum plate outer film changes due to different metallurgical reasons, and the internal structure of the aluminum plate and crystal structure change, so the mechanical behavior and electrochemical behavior of the aluminum plate will be affected, which also makes the stress corrosion of the aluminum plate different.

2. Causes of stress

Among the reasons for the stress corrosion of aluminum plate, the factors mainly include oxygen and other gases, corrosion inhibitors, temperature, pressure, ion types, ion concentrations, solution pH value, etc. In fact, the stress corrosion of aluminum plates in different atmospheres is not the same, through the study of stress corrosion of 7A04 and 2A12 in different atmospheres, it is found that the stress corrosion of aluminum plates in the ocean is relatively more. This is because the ocean contains a lot of salt, and CI will pass through the film on the outer surface of the aluminum plate and enter the interior, resulting in corrosion.

Experiments have proved that the corrosion of aluminum plate is aggravated, generally when the concentration of HNO^3 solution reaches between 20% and 40%, when the concentration is 35%, the corrosion rate of aluminum plate reaches the point. However, the stress corrosion of the aluminum plate is not obvious in the concentrated HNO^3 solution, because a dense oxide film is formed on the surface of the aluminum plate to prevent further corrosion of HNO^3. Haomei Aluminum Co., Ltd. is an earlier established aluminum plate manufacturer in China, we have all grades of aluminum plate, if you want to buy please contact us.