Analysis of corrosion resistance of magnesium duct in humid or corrosive environment
Publish Time: 2025-02-07
As a lightweight and high-strength material, magnesium duct has shown wide application potential in many industrial fields. However, its corrosion resistance, especially in humid or corrosive environments, has always been the focus of industry attention.The corrosion of magnesium alloys is essentially an electrochemical and chemical process in which magnesium is oxidized into magnesium oxide or magnesium hydroxide. In a dry, low-humidity environment, a dense oxide layer is easily formed on the surface of magnesium alloys, which can resist the erosion of corrosive substances to a certain extent, making magnesium alloys show good corrosion resistance. However, when the environment becomes humid or corrosive substances exist, the situation is quite different.In a humid environment, the oxide layer on the surface of magnesium alloys is easily converted into magnesium hydroxide, and magnesium hydroxide reacts with carbon dioxide in the atmosphere to generate magnesium carbonate. The surface film formed by these substances cannot effectively prevent the internal magnesium from continuing to react with the outside world. Especially in an environment containing chloride ions or other highly corrosive ions, the corrosion rate of magnesium alloys will be significantly accelerated. Chloride ions can destroy the protective film on the surface of magnesium alloys, making them more vulnerable to corrosion.In addition, magnesium alloys are also at risk of stress corrosion cracking. In a humid or corrosive environment, magnesium alloys may crack even if the tensile stress has not reached half of the yield strength. This stress corrosion cracking phenomenon is usually caused by the hydrogen embrittlement mechanism. Hydrogen atoms can easily enter magnesium and magnesium alloys and react with magnesium to form magnesium hydride, thereby affecting the bond strength between metal atoms and causing cracking.In order to improve the corrosion resistance of magnesium duct in a humid or corrosive environment, a variety of measures can be taken. For example, adding a small amount of zinc, manganese, aluminum and other elements through alloying can improve the corrosion resistance of magnesium alloys. In addition, surface treatment of magnesium duct, such as electroplating, chemical plating, chemical conversion coating and thermal spraying, can also effectively improve its surface properties and enhance corrosion resistance.In summary, the corrosion resistance of magnesium duct in a humid or corrosive environment is relatively weak, but through reasonable alloying design and surface treatment, its corrosion resistance can be significantly improved to meet the needs of more application scenarios. In practical applications, it is necessary to select appropriate magnesium duct materials and protective measures according to the specific use environment and requirements.
