Surface cleaning method of seamless steel tube

Ensuring the cleanliness of seamless steel tubes is essential for their durability and performance, especially in applications involving fluid transportation. The following methods are commonly used for cleaning the surfaces of seamless steel tubes.

1. Cleaning

Solvents and emulsions are used to clean the steel surface to remove oil, grease, dust, lubricants, and similar organic substances. However, this method does not remove rust, oxide scale, or welding flux, making it suitable only as an auxiliary means in anti-corrosion production.

2. Tool Rust Removal

Wire brushes and other tools are used to grind the surface of the steel, removing loose or raised oxide scale, rust, and welding slag. Manual rust removal can achieve a Sa2 level, while power tools can achieve a Sa3 level. However, if the steel surface is covered with a firm scale of iron oxide, the rust removal effect is not ideal, and the required anchor pattern depth for anti-corrosion construction is not achieved.

3. Pickling

Pickling generally involves chemical and electrolytic methods. For pipeline anti-corrosion, chemical pickling is used to remove oxide scale, rust, and old coatings. Although chemical cleaning can achieve a certain degree of cleanliness and roughness, it creates a shallow anchor pattern and may cause environmental pollution.

4. Spray (Throwing) Rust Removal

This method involves using a high-power motor to drive spraying (throwing) blades to rotate at high speed. Abrasives like steel sand, steel shot, iron wire segments, and minerals are sprayed (thrown) onto the steel pipe surface under centrifugal force. This process not only removes rust, oxides, and dirt but also imparts the required uniform roughness to the steel pipe through abrasive impact and friction.

Seamless steel pipes, with their hollow sections, are widely used as pipelines for transporting fluids such as oil, natural gas, gas, water, and certain solid materials. Compared to solid steel like round steel, seamless steel pipes are lighter in weight while maintaining the same bending and torsional strength, making them an economical choice.

Advantages of Spray (Throwing) Rust Removal

- Enhanced Physical Adsorption: The process increases the physical adsorption on the pipe surface.

- Improved Mechanical Adhesion: It enhances the mechanical adhesion between the anti-corrosion layer and the pipe surface.

- Ideal for Pipeline Anti-Corrosion: Spray (throwing) rust removal is considered the best method for pipeline anti-corrosion.

Typically, shot blasting (sand) rust removal is used for the inner surface treatment of pipes, while shot blasting (sand) is used for the outer surface treatment. By employing these methods, the cleanliness and quality of seamless steel tubes are ensured, optimizing their performance in various industrial applications.