Corrosion and protection are topics we can never discuss exhaustively

Using stainless steel for these support components eliminates the need for anti-corrosion measures and also improves their appearance. It’s just a bit more expensive.

Mr. Wang, could you talk about the material selection in this regard and the precautions to take during actual use?

Characteristics of steel structure corrosion and protection methods: Steel structures such as bridges, TV towers, and high-voltage transmission towers, etc； Offshore oil production facilities and the steel structures of offshore platforms are all exposed to marine and industrial atmospheric corrosion environments for extended periods of time. For long-term use without the need for extensive repairs, durable coatings are generally used for protection; they can last from 5 to 30 years, result in lower repair costs, and offer significant economic benefits. 1. Corrosion characteristics of steel structures in marine and industrial atmospheres. Steel structures in atmospheric environments are exposed to sunlight, wind and sand, rain and snow, frost and dew, as well as changes in temperature and humidity throughout the year; oxygen and moisture in the atmosphere are key factors that cause corrosion of steel structures outdoors. Industrial gases contain substances such as SO2, CO2, NO2, Cl-, H2S, and NH3. Although their concentrations are low, their corrosive effects on steel cannot be ignored; among these, SO2 has the greatest impact, followed by CO2, chlorides, and many other pollutants. When these gases dissolve in water, they become acidic, forming acid rain that corrodes metal structures. Therefore, the atmosphere in chemical plants causes particularly severe metal corrosion. The marine atmosphere is characterized by a high content of salts, primarily NaCl. These salt particles settle on metal surfaces; due to their hygroscopic nature and their ability to increase the conductivity of the surface film, coupled with the strong corrosive properties of Cl-, this accelerates the corrosion of the metal surfaces. The closer a steel structure is to the coast, the more severe its corrosion becomes, with its corrosion rate being many times higher than that in inland areas with normal atmospheric conditions. 2. Common protection methods for steel structures: Zinc or aluminum spraying is often used for steel structures, along with corrosion-resistant coatings to create a long-lasting anti-corrosion system; alternatively, specialized heavy-duty corrosion-resistant coatings can be applied for protection. Metal zinc and aluminum possess excellent resistance to atmospheric corrosion. Zinc or aluminum is sprayed on steel components; zinc and aluminum have a negative potential, and they act as sacrificial anodes to protect the steel, thereby providing effective protection for it. Currently, aluminum spraying coatings are used to prevent corrosion in industrial and marine atmospheres, and their advantages are as follows: (1) The aluminum spraying coating has a strong bond with the steel substrate, offers a long service life, and results in good economic benefits over the long term ； ⑵Flexible in application, suitable for long-term protection of important large-scale and difficult-to-maintain steel structures; can be installed on-site ； ⑶ Zinc or aluminum spraying followed by the application of an anti-corrosion coating can **extend the service life of the coating. Both theoretically and in practical applications, zinc or aluminum coatings serve as the best base layer for anti-corrosion coatings. The protective lifespan of a composite coating that combines a metal spray coating with an anti-corrosion coating is longer than the sum of the lifespans of the metal spray coating and the anti-corrosion coating alone, and it is several times longer than the lifespan of a coating applied as a single layer. From the perspective of long-term cost efficiency, aluminum spraying is the most economical option, although it requires a high initial investment; a well-applied coating can remain maintenance-free for up to 10 years. 3. The heavy-duty anti-corrosion long-lasting coating consists of a primer, an intermediate coat, and a topcoat. The epoxy zinc-rich primer + epoxy ferrochrome intermediate coat + acrylic polyurethane long-term protection system offers good cost-effectiveness. A fluorocarbon coating can also be used as the surface layer. The features are as follows: Acrylic polyurethane topcoat. Since acrylic polyurethanes do not absorb ultraviolet light and sunlight with wavelengths above 300nm, coatings composed of hydroxyacrylic resins and aliphatic isocyanate crosslinking agents exhibit excellent weather resistance, light resistance, and color retention; they also have a thick paint film, high impact resistance, and good elasticity. Component A is prepared using acrylic resin, solvents, color fillers, and additives, while Component B is an aliphatic isocyanate; this combination yields a coating with excellent weather resistance and corrosion resistance. This type of paint has been used on metal surfaces in chemical processing environments for over 6 years, and the coating remains intact, whereas coatings such as chlorosulfonated rubber applied during the same period have shown signs of flaking and peeling. Currently, the use of this complete system is the mainstream for paints used on steel structures in the petrochemical and chemical industries. Fluorocarbon anti-corrosion coatings are coatings whose main film-forming components are organic fluorocarbon polymers or organofluorine-modified polymers. Their key advantages lie in their excellent weather resistance, resistance to chemical agents, corrosion resistance, wear resistance, and resistance to staining. This paint can be used in highly corrosive conditions; it can be considered for use in C5I environments. This paint is relatively expensive, so it is necessary to conduct a thorough economic analysis before using it. In short, the above are my personal views. However, as society progresses, better materials will emerge to replace the existing ones. This requires us to keep learning and practicing in our future work in order to discover better materials, thereby extending the service life of anti-corrosion coatings and achieving the best economic benefits.

Characteristics of steel structure corrosion and protection methods: Steel structures such as bridges, TV towers, and high-voltage transmission towers, etc； Offshore oil production facilities and the steel structures of offshore platforms are all exposed to marine and industrial atmospheric corrosion environments for extended periods of time. For long-term use without the need for extensive repairs, durable coatings are generally used for protection; they can last from 5 to 30 years, result in lower repair costs, and offer significant economic benefits. 1. Corrosion characteristics of steel structures in marine and industrial atmospheres. Steel structures in atmospheric environments are exposed to sunlight, wind and sand, rain and snow, frost and dew, as well as changes in temperature and humidity throughout the year; oxygen and moisture in the atmosphere are key factors that cause corrosion of steel structures outdoors. Industrial gases contain substances such as SO2, CO2, NO2, Cl-, H2S, and NH3. Although their concentrations are low, their corrosive effects on steel cannot be ignored; among these, SO2 has the greatest impact, followed by CO2, chlorides, and many other pollutants. When these gases dissolve in water, they become acidic, forming acid rain that corrodes metal structures. Therefore, the atmosphere in chemical plants causes particularly severe metal corrosion. The marine atmosphere is characterized by a high content of salts, primarily NaCl. These salt particles settle on metal surfaces; due to their hygroscopic nature and their ability to increase the conductivity of the surface film, coupled with the strong corrosive properties of Cl-, this accelerates the corrosion of the metal surfaces. The closer a steel structure is to the coast, the more severe its corrosion becomes, with its corrosion rate being many times higher than that in inland areas with normal atmospheric conditions. 2. Common protection methods for steel structures: Zinc or aluminum spraying is often used for steel structures, along with corrosion-resistant coatings to create a long-lasting anti-corrosion system; alternatively, specialized heavy-duty corrosion-resistant coatings can be applied for protection. Metal zinc and aluminum possess excellent resistance to atmospheric corrosion. Zinc or aluminum is sprayed on steel components; zinc and aluminum have a negative potential, and they act as sacrificial anodes to protect the steel, thereby providing effective protection for it. Currently, aluminum spraying coatings are used to prevent corrosion in industrial and marine atmospheres, and their advantages are as follows: (1) The aluminum spraying coating has a strong bond with the steel substrate, offers a long service life, and results in good economic benefits over the long term ； ⑵Flexible in application, suitable for long-term protection of important large-scale and difficult-to-maintain steel structures; can be installed on-site ； ⑶ Zinc or aluminum spraying followed by the application of an anti-corrosion coating can **extend the service life of the coating. Both theoretically and in practical applications, zinc or aluminum coatings serve as the best base layer for anti-corrosion coatings. The protective lifespan of a composite coating that combines a metal spray coating with an anti-corrosion coating is longer than the sum of the lifespans of the metal spray coating and the anti-corrosion coating alone, and it is several times longer than the lifespan of a coating applied as a single layer. From the perspective of long-term cost efficiency, aluminum spraying is the most economical option, although it requires a high initial investment; a well-applied coating can remain maintenance-free for up to 10 years. 3. The heavy-duty anti-corrosion long-lasting coating consists of a primer, an intermediate coat, and a topcoat. The epoxy zinc-rich primer + epoxy ferrochrome intermediate coat + acrylic polyurethane long-term protection system offers good cost-effectiveness. A fluorocarbon coating can also be used as the surface layer. The features are as follows: Acrylic polyurethane topcoat. Since acrylic polyurethanes do not absorb ultraviolet light and sunlight with wavelengths above 300nm, coatings composed of hydroxyacrylic resins and aliphatic isocyanate crosslinking agents exhibit excellent weather resistance, light resistance, and color retention; they also have a thick paint film, high impact resistance, and good elasticity. Component A is prepared using acrylic resin, solvents, color fillers, and additives, while Component B is an aliphatic isocyanate; this combination yields a coating with excellent weather resistance and corrosion resistance. This type of paint has been used on metal surfaces in chemical processing environments for over 6 years, and the coating remains intact, whereas coatings such as chlorosulfonated rubber applied during the same period have shown signs of flaking and peeling. Currently, the use of this complete system is the mainstream for paints used on steel structures in the petrochemical and chemical industries. Fluorocarbon anti-corrosion coatings are coatings whose main film-forming components are organic fluorocarbon polymers or organofluorine-modified polymers. Their key advantages lie in their excellent weather resistance, resistance to chemical agents, corrosion resistance, wear resistance, and resistance to staining. This paint can be used in highly corrosive conditions; it can be considered for use in C5I environments. This paint is relatively expensive, so it is necessary to conduct a thorough economic analysis before using it. In short, the above are my personal views. However, as society progresses, better materials will emerge to replace the existing ones. This requires us to keep learning and practicing in our future work in order to discover better materials, thereby extending the service life of anti-corrosion coatings and achieving the best economic benefits.

Using stainless steel is an option, but thickness and load capacity also need to be taken into consideration... which affects the construction cost. Painting is a good method, but it’s important to choose the right type of paint. Additionally, the painting technique and the quality of installation are of utmost importance. Finally, I think anti-corrosion waxes and polyurethanes are also excellent choices. The above information is provided for reference only

That’s true; corrosion prevention is a highly comprehensive field that requires knowledge and skills in various areas.

I think the biggest technical challenge in corrosion prevention lies in quality control during the construction process, rather than various paint formulas and anti-corrosion methods. Have you noticed that, generally, equipment that has undergone anti-corrosion treatment in a manufacturing facility has a more durable protective layer than that which is treated on-site; on-site anti-corrosion measures are basically just a form of deception.

I worked on operation and maintenance in petrochemical plants for five years, and then spent six years working on the project management of coal-fired power and chemical industry projects. I have also been involved in photovoltaic systems, biomass power generation, and integrated energy services. Recently I started working in corrosion prevention, and there is still much for me to learn*