What materials are best for protecting the surface of steel from corrosion?
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What materials are best for protecting the surface of steel from corrosion? sewer pipes
Is it for interior wall corrosion protection or exterior wall corrosion protection?
The types of corrosion that affect the outer wall include soil corrosion, bacterial corrosion, and stray current corrosion. The general treatment involves applying a protective coating to the outer surface. If the rust removal of the steel pipe reaches St3 level, apply two coats of iron red primer followed by two coats of silver powder topcoat. This type of coating is a traditional method for preventing atmospheric corrosion; it offers advantages such as strong rust resistance, cost-effectiveness, and ease of application. The types of corrosion that can affect interior walls include chemical corrosion, electrolytic corrosion, and oxygen corrosion. The general treatment is also applying a coating protective layer. Now, many sewage pipes are made of polymer materials, rather than concrete pipes.
Exterior wall: Epoxy thick paste paint or epoxy thick paste aluminum powder paint, or epoxy coal tar pitch. Inner wall: Epoxy thick paste paint, aluminum powder paint, or epoxy glass flake coating. It is necessary to ensure an adequate coating thickness, of at least 300 microns or more.
Depending on the actual operating conditions, various methods can be chosen; generally, an anti-corrosion coating system is used at room temperature, consisting of an epoxy zinc-rich primer, an epoxy ferrochrome intermediate coat, and a polyurethane top coat, following a 2+1+2 configuration. It can be engraved; if it is a thick-paste epoxy coal tar pitch paint that comes into contact with the surface, that’s sufficient
Apply anti-rust paint, and attach a zinc block
How long is the required anti-corrosion time? Is the shape of the part complex?
For steel used in different applications, the anti-corrosion solutions vary: for the surfaces of simple daily items, galvanizing and passivation techniques are sufficient to address the issue； For equipment that requires protection for a short period of time in outdoor conditions, Dacromet, zinc plating, and a single base coat can be used ； For steel structures used in applications that require long-term protection, such as bridges and dams, composite coating systems must be employed to extend their protective lifespan. Additionally, the operating environment of the equipment and the difficulty of maintenance are also factors considered in designing protection schemes.
The service life is designed based on specific working conditions; it’s not a matter of stating things one by one