SSAW steel pipe surface treatment method

The surface of SSAW (Spiral Submerged Arc Welded) steel pipes can undergo various changes depending on the environmental conditions they are exposed to. Effective surface treatment is essential to enhance the pipe’s durability and corrosion resistance. Here are some common methods for treating SSAW steel pipes.

Cleaning:
Solvent and emulsion are used to clean the surface of SSAW steel pipes, removing oil, grease, dust, smoothing agents, and other organic materials. However, this method does not remove rust, oxide scale, flux, or other inorganic contaminants. It serves as an auxiliary step in the anti-corrosion production process for SSAW steel pipes.

Rust Removal with Tools:
The SSAW steel pipe is polished using wire brushes, which helps remove loose or elevated scale, rust, welding slag, and other contaminants. Manual rust removal typically achieves an SA2 cleanliness level, while power tools can reach an SA3 level. However, if the pipe surface has a heavy layer of iron oxide scale, the tool rust removal may not be as effective.

Pickling:
Chemical and electrolytic pickling methods are commonly used to treat the surface of SSAW steel pipes. Chemical pickling can remove oxide scale, rust, and old coatings and is typically applied after rust removal. This method ensures a certain level of cleanliness and roughness, but the anchor pattern created by chemical cleaning tends to be shallow, making the surface more susceptible to contamination.

Abrasive Blasting:
Abrasive blasting involves using a high-speed motor to rotate spray blades, which propel abrasives such as steel grit, steel shot, wire segments, and minerals onto the surface of the SSAW steel pipe under centrifugal force. This process effectively removes rust, oxides, and dirt. The abrasive impact and friction also help achieve the required surface roughness for better anti-corrosion coating adhesion. After blasting and rust removal, the mechanical bond between the anti-corrosion layer and the pipe’s surface is strengthened.

Applications:

- Sandblasting: Primarily used for both internal and external pipe treatment, sandblasting is highly effective for descaling.

- Shot Blasting: Mainly used for exterior pipe surface treatment, shot blasting is highly effective for ensuring proper surface roughness.

By employing these surface treatment techniques, the longevity and corrosion resistance of SSAW steel pipes are significantly enhanced, making them more reliable in various industrial applications.