Corrosion has always been the primary factor affecting the service life of aluminum plates. Although the aluminum plate processed by a certain process can be used in a complex environment, due to many factors that cause the aluminum plate to corrode, no matter how perfect the processing process is, it cannot guarantee that the aluminum plate will not be corroded. There are three main reasons for aluminum plate corrosion: environmental factors, metallurgical factors and stress factors

1. Environmental factors The main environmental factors that affect the stress corrosion of aluminum plates are: ion species, ion concentration, solution pH, oxygen and other gases, corrosion inhibitors, environmental temperature, environmental pressure, etc. The stress corrosion conditions of 2A12 and 7A04 aluminum plates in different atmospheric environments were studied, and it was found that the stress corrosion sensitivity of aluminum plates in different environments is different, and the marine environment is more sensitive. The marine environment contains a lot of salt, and Cl- will pass through the maintenance film on the surface of the aluminum plate and enter the interior, causing corrosion to it. The experiment shows that when the mass concentration of HNO3 solution is between 20% and 40%, the corrosion of the aluminum plate is intensified, and the corrosion rate of the aluminum plate reaches the highest point when the concentration is about 35%. In the concentrated HNO3 solution, the stress corrosion of the aluminum plate is not obvious. The reason for this phenomenon is that a dense oxide film is formed on the surface of the aluminum plate, which prevents further corrosion of HNO3.

2. Metallurgical factors Metallurgical factors mainly include the influence of casting methods, processing methods and hot stress corrosion of gold. It is found that cathodic polarization increases the stress corrosion sensitivity of aluminum plates, and the stress corrosion sensitivity of friction stir welding is lower than that of fusion welding. It is generally believed that the 6061-T6 and 3004 aluminum plates that have been properly treated will not corrode. The different metallurgical factors change the type of the outer surface film of the aluminum plate, and cause the difference in the internal structure of the aluminum plate and the change of the crystal structure, thereby affecting the electrochemical and mechanical behavior of the aluminum plate, resulting in different stress corrosion sensitivity of the aluminum plate.

3. Stress factors Stress factors mainly include load type, load size, load direction, load speed, etc. As far as corrosion is concerned, the direction of stress must be perpendicular to the grain boundaries in order to be able to separate them. One of the key factors in the occurrence of stress corrosion is stress. Different stress effects will produce different effects. Corrosion fatigue caused by the combined action of alternating stress and environment is usually significantly different from stress corrosion cracking caused by fixed stress. Corrosion fatigue is usually more serious than stress corrosion. In addition, the difference in loading speed will also affect the sensitivity of the aluminum plate to stress corrosion. Learn more aluminum plate knowledge https://www.aluminum-price.com/