Rust removal method of ERW straight seam steel pipe

During the anti-corrosion construction process of oil and gas pipelines, the surface treatment of ERW straight seam steel pipes is one of the key factors that determine the anti-corrosion service life of the pipeline. It is the prerequisite for whether the anti-corrosion layer and the ERW steel pipe can be firmly combined. According to research by professional institutions, in addition to factors such as coating type, coating quality and construction environment, the life of the anti-corrosion layer depends on factors such as the surface treatment of ERW steel pipes, which accounts for about 50% of the impact on the life of the anti-corrosion layer. Therefore, the anti-corrosion layer should be strictly followed Standardize the requirements for the surface of ERW steel pipes and continuously improve the surface treatment methods of ERW straight seam steel pipes. 

Below, the carbon steel pipe manufacturer will introduce to you several common rust removal methods for ERW pipes:

1. Cleaning

Solvents and emulsions are used to clean the steel surface to remove oil, grease, dust, lubricants and similar organic matter. However, it cannot remove rust, oxide scale, welding flux, etc. on the steel surface, so it is only used as an auxiliary means in defense operations.

2. Pickling

Generally, chemical and electrolytic methods are used for pickling treatment. Only chemical pickling is used for pipeline anti-corrosion, which can remove scale, rust, and old coatings. Sometimes it can be used as a reprocessing after sandblasting and rust removal. Although chemical cleaning can achieve a certain degree of cleanliness and roughness on the surface, its anchor lines are shallow and it is easy to cause pollution to the surrounding environment.

3. Tool rust removal

Mainly use tools such as wire brushes to polish the steel surface to remove loose scale, rust, welding slag, etc. The rust removal of hand tools can reach Sa2 level, and the rust removal of power tools can reach Sa3 level. If the iron oxide scale is firmly attached to the surface of the steel, the rust removal effect of the tool will not be ideal and the anchor pattern depth required for anti-corrosion construction will not be achieved.

4. Spray rust removal

Spray rust removal uses a high-power motor to drive the spray blades to rotate at high speed, so that steel shot, steel sand, iron wire segments, minerals and other abrasives are sprayed on the surface of the straight seam steel pipe under the powerful centrifugal force of the motor. It can not only completely remove oxides , rust and dirt, and the straight seam steel pipe can achieve the required uniform roughness under the action of violent impact and friction of abrasives.

After spray rust removal, it can not only expand the physical adsorption effect on the pipe surface, but also enhance the mechanical adhesion between the anti-corrosion layer and the pipe surface. Therefore, spray rust removal is an ideal rust removal method for pipeline anti-corrosion. Generally speaking, shot blasting is mainly used for inner surface treatment of pipes, and shot blasting is mainly used for outer surface treatment of straight seam steel pipes.

During the production process, technical indicators related to rust removal must be strictly required to prevent damage to ERW straight-seam steel pipes due to operational errors. After ERW steel pipes are de-embroidered, the appearance of the product will be smoother than before de-embroidery. The de-embroidery of ERW pipes It is a frequently used technology in the steel pipe industry.

Tips: Carbon steel welded pipes can be divided into three types: straight seam submerged arc welded steel pipes, spiral welded steel pipes, and high-frequency straight seam welded steel pipes (Electric Resistance Welded Steel Pipe) according to the forming method of the weld seam.