Surface treatment methods for anti-corrosion spiral steel pipes

To ensure reliable anti-corrosion performance and extend the service life of spiral steel pipes, proper surface treatment before coating is essential. Different treatment methods serve different purposes, and in practice they are often used in combination to achieve the required cleanliness and surface roughness.

Solvent or Emulsion Cleaning
Cleaning the surface of anti-corrosion spiral steel pipes with solvents or emulsions is mainly used to remove organic contaminants such as oil, grease, and dust. However, this method cannot eliminate rust, mill scale, or welding flux. Therefore, it is generally used only as an auxiliary pretreatment step rather than a standalone solution.

Mechanical Grinding and Brushing
Mechanical surface treatment using tools such as wire brushes, grinding wheels, or sandpaper can effectively remove loose rust, scale, welding slag, and other poorly adhered impurities. This method is suitable for local treatment or for improving surface conditions before more advanced anti-corrosion processes.

Chemical Pickling Treatment
Chemical pickling is commonly applied in spiral steel pipe anti-corrosion preparation to remove rust, oxide scale, and old coating layers. In addition to improving surface cleanliness, pickling can also create a certain level of surface roughness, which helps enhance coating adhesion.

Shot Blasting / Sand Blasting Treatment
Shot blasting or sand blasting uses a high-power motor to drive blasting wheels at high speed, propelling steel grit, steel shot, iron wire segments, or mineral abrasives onto the pipe surface under centrifugal force. This process thoroughly removes rust, oxides, and contaminants, while simultaneously forming a uniform surface roughness through strong impact and friction, meeting the requirements for high-performance anti-corrosion coatings.

These surface treatment methods form the foundation of effective anti-corrosion systems for spiral steel pipes and should be selected based on project requirements, coating type, and service environment.