With the rapid development of the domestic energy industry, the application of stainless steel pipes is also rapidly increasing. Among them, in the anti-corrosion construction process of oil and gas pipelines, the surface treatment of stainless steel pipes is one of the key factors that determine the anti-corrosion service life of the pipeline. An important prerequisite for a strong combination. According to authoritative certification, the service life of the anti-corrosion layer depends on the type of coating, coating quality and construction environment. The appearance of the stainless steel pipe accounts for about half of the impact on the life. Therefore, it is necessary to strictly follow the anti-corrosion coating specifications for stainless steel The surface requirements of the pipes continuously optimize the surface treatment process of stainless steel pipes.

Nowadays, the common surface treatment methods of stainless steel pipes mainly include cleaning, rust removal, pickling, etc. These methods are introduced below.

Cleaning

The use of solvents and emulsions to clean the surface of stainless steel materials can remove oil, grease, dust, lubricants and similar organic matter, but this method cannot remove the rust, oxide scale, welding flux, etc. on the surface of stainless steel materials, so it is only a kind of anti-corrosion production. Kind of auxiliary means.

Tools for rust removal

Generally use wire brushes and other things to polish the appearance of stainless steel, which can remove loose or warped oxide scale, rust, welding slag, etc. Manual tool derusting can reach Sa2 level, and power tool derusting can reach Sa3 level. If the stainless steel material is adhered to the surface of strong oxide scale, the derusting effect of the tool is not ideal, and the anchor pattern depth required by the anti-corrosion construction cannot be reached.

Pickling

There are usually two methods for pickling treatment, chemical and electrolysis. Only chemical pickling is used for anticorrosion of stainless steel pipes, which can remove oxide scale, rust, and old coatings. Sometimes this method can be used as a reprocessing after sandblasting and rust removal. . Although chemical cleaning can make the appearance reach a certain degree of cleanliness and roughness, its anchor lines are shallow and easily pollute the environment.

Spray (throwing) shooting to remove rust

Spraying (throwing) rust removal is to drive the spraying (throwing) blades to rotate at a high speed through a high-power motor, so that the steel grit, steel shot, iron wire section, minerals and other abrasives are sprayed (thrown) on the surface of the steel pipe under the action of centrifugal force. , Not only can completely remove rust, oxides and dirt, but also the stainless steel tube can reach the required uniform roughness under the action of the violent impact and friction of the abrasive.

After spraying (throwing) to remove the rust, not only can the physical adsorption of the stainless steel pipe surface be expanded, but also the mechanical adhesion of the anti-corrosion layer and the pipe surface can be enhanced. Therefore, spray (throwing) rust removal is an ideal way to remove rust from pipelines. Generally speaking, shot blasting (sand) rust removal is mainly used for pipe inner and outer surface treatment, and shot blasting (sand) rust removal is mainly used for pipe outer surface treatment.