Embroidery removal technology of submerged arc welded steel pipe

According to the anti-corrosion coating standards for large-diameter submerged arc steel pipes, the methods for surface treatment of these pipes are continuously improved. This article discusses the various techniques for removing surface impurities from submerged arc welded steel pipes.

Cleaning:

Purpose: Use solvents and emulsions to clean the steel surface, removing oil, grease, dust, and similar organic matter.

Limitations: This method cannot remove rust, oxide scale, or welding flux from the steel surface and is typically used as a preliminary step in anti-corrosion treatment.

Pickling:

Methods: Chemical and electrolysis methods are commonly used for pickling. In pipeline anti-corrosion, only chemical pickling is used.

Effectiveness: This method removes oxide scale, rust, and old coatings, and can sometimes be combined with sandblasting for rust removal.

Drawbacks: Chemical pickling can achieve a certain degree of cleanliness and roughness, but the anchor pattern is shallow and can pollute the surrounding environment. Meide Steel Control Manufacturing Co., Ltd. advises against this method.

Mechanical Tools for Rust Removal:

Tools: Wire brushes and similar tools are used to polish the steel surface, removing loose oxide scale, rust, and welding slag.

Effectiveness: Hand tools can achieve an SA2 level of rust removal, while power tools can reach an SA3 level. However, if the steel surface has adhered to strong oxide scale, these tools may not achieve the desired results or the necessary anchor pattern depth for anti-corrosion treatment.

Radiation Rust Removal:

Process: A high-power motor drives radiating blades at high speed, propelling steel shots, grit, iron wire segments, minerals, and other abrasives onto the steel pipe surface using strong centrifugal force.

Benefits: This method effectively removes oxides, rust, and dirt. The submerged arc steel pipe achieves the required average roughness due to the abrasive impact and friction, enhancing the physical adsorption and mechanical adhesion of the anti-corrosion layer to the pipe surface.

Recommendation: Meide Steel Control Manufacturing Co., Ltd. strongly recommends radiation rust removal as it is a comprehensive rust removal method. Shot blasting should be employed for both internal and external surface treatment of the pipes.

The above methods provide various levels of effectiveness for anti-corrosion preparation of submerged arc welded steel pipes. Cleaning and pickling serve as preliminary steps, while mechanical tools and radiation rust removal offer more thorough solutions. Radiation rust removal, particularly shot blasting, is the most effective method, ensuring optimal adhesion and long-term protection of the anti-corrosion coating.