What Cause the Corrosion in Air Storage Tanks

 
 
Air storage tanks, as indispensable equipment in industrial production and daily life, are inevitably exposed to the natural environment for extended periods, leading to various forms of corrosion. This article will delve into the causes of corrosion in air storage tanks and the factors influencing it, aiming to provide references for the maintenance and management of air storage tanks.
 
Causes of Corrosion in Air Storage Tanks
 
During their use, air storage tanks are subject to corrosion due to the action of moisture, oxygen, acidic pollutants, and other substances in the atmosphere. This type of corrosion is particularly common in steel materials, manifesting as rusting. Corrosion not only affects the appearance of the air storage tank but can also reduce its performance and even lead to safety hazards.
 
Types of Atmospheric Corrosion
 
1. Dry Atmospheric Corrosion: In a dry atmosphere, a layer of invisible oxide film forms on the metal surface, maintaining the metal's luster, but this protective effect is limited.
 
2. Humid Atmospheric Corrosion: When the water vapor concentration in the atmosphere reaches the critical humidity of the metal, a thin layer of water film forms on the metal surface, leading to uniform corrosion. If pollutants such as CO2, H2S, and SO2 are present in the atmosphere, the rate of corrosion will significantly increase.
 
3. Corrosion under Visible Liquid Film Conditions: Under conditions of high humidity or rainwater, a visible layer of water film forms on the metal surface, accelerating the corrosion process.
 
Influencing Factors of Atmospheric Corrosion
 
1. The Impact of Water: Water, as the primary factor of corrosion, has its electrolytic properties and the ability to dissolve a large number of ions, leading to metal corrosion. Additionally, the dissociation of water into H+ and OH-, with different pH values, has a significant impact on the dissolution and corrosion of metals and oxides.
 
2. The Impact of SO2: In areas heavily polluted by industrial emissions, SO2 has the most severe impact on the corrosion of steel. The corrosion rate of steel plates increases with the concentration of SO2 in the atmosphere.
 
3. The Impact of Marine Atmosphere: The atmosphere near the ocean contains salts, mainly NaCl, with Cl- having a strong corrosive effect, thus accelerating the corrosion process.
 
4. Other Influences: In the atmospheric environment of oil production, there may be a large amount of harmful substances such as Cl2, NH3, H2S, and solid dust particles. The corrosion of steel in air storage tanks also increases with the content of these substances.
 
The corrosion of air storage tanks is a complex process influenced by various factors. To extend the service life of air storage tanks and ensure their safe operation, it is necessary to have a full understanding of the causes of corrosion and influencing factors, and to take corresponding protective measures. This may include regular inspections, cleaning, coating protection, and environmental control to slow down the rate of corrosion and protect air storage tanks from atmospheric corrosion.