Carbon steel pipe coating

by Zhi shang Metallic material

Carbon steel tubes can be provided in uncoated (bare) form, or they can be temporarily coated with an external coating in order to minimize rust during transportation and storage. In addition, according to specific requirements, special anti-corrosion coatings can also be provided.

When it is necessary to provide hot-dip galvanized steel pipes, the steel pipes need to be completely descaled and cleaned if necessary. Then, at the appropriate temperature, the steel pipe is immersed in a molten zinc bath with a zinc content of not less than 98.5%. In this way, the inside and outside of the steel pipe are protected by hot dip galvanizing.

For underground and underground lines and fluid transfer lines, special anti-corrosion coatings such as 3PE, FBE and 3PP are required. Before anti-corrosion treatment, ensure that the outer surface of the pipe is free of harmful levels of contaminants such as oil, grease and salt. The pipe should be preheated to remove moisture before sandblasting. The level of sand blasting and the thickness of the coating shall meet the requirements of the standard. In addition, the cutting length at both ends should be 50-20mm or the specified length.

The surface treatment methods of carbon steel pipes are as follows:

Hot dip galvanizing treatment method: Hot dip galvanizing is to soak carbon steel pipe in molten zinc liquid, so that a layer of zinc-iron alloy layer is formed on its surface, so that it has excellent corrosion resistance. Before hot dip galvanizing, it is necessary to pickling, cleaning and surface pretreatment of the pipe to ensure the adhesion and uniformity of the zinc-iron alloy layer.

Sandblasting treatment method: Sandblasting is the use of high-speed sand impact to polish the surface of the pipe, remove the surface of the oxide, oil and other impurities, in order to achieve a flat, smooth surface treatment effect. This can improve the adhesion and beauty of the paint. The sand blasting method can choose different size particles and sand blasting pressure according to the different material and surface roughness.

Grinding treatment method: Grinding is the mechanical grinding and polishing of the surface of the carbon steel pipe to obtain a bright and smooth surface effect. This method is suitable for occasions requiring high aesthetics, such as home decoration, sculpture, etc., and carbon steel pipes requiring strong coating adhesion.

Pickling treatment method: Pickling is the use of strong acid or acidic solution on the surface of carbon steel pipe chemical corrosion treatment, remove the surface of the oxide and oil and other impurities, in order to achieve a flat, clean surface effect. There are many pickling methods, it is necessary to choose the appropriate pickling method according to the specific situation, in order to reduce the pollution to the environment.