Rust removal of CS seamless pipe

Posted by chase Liu on January 30th, 2023

CS seamless pipe has a hollow section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, steel pipes have a lighter weight in terms of flexural and torsional strength, and are economical cross-section steels. Widely used in the production of structural parts and mechanical parts, such as oil drill pipes, car drive shafts, bicycle frames, and steel scaffolding used in building construction.The use of steel pipes to make ring parts can improve the utilization rate of materials, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sets, etc., which have been widely used in steel pipes. Steel pipe is still an indispensable material for various conventional weapons, and barrels, barrels, etc. must be made of steel pipes. Steel pipes can be divided into round pipes and special-shaped pipes according to the shape of the cross-sectional area. Because under the condition that the circumferences are equal, the circle area is the largest, and more fluids can be transported with circular tubes. In addition, when the ring section receives internal or external radial pressure, the force is relatively uniform, so most steel pipes are round pipes.

rust removal method

1. Tool derusting. Mainly use tools such as wire brushes to polish the steel surface, which can remove loose or raised scale, rust, welding slag, etc. The rust removal by hand tools can reach Sa2 level, and the power tool rust removal 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 is not ideal, and the anchor pattern depth required for anti-corrosion construction cannot be reached.

2. Spray (throw) to remove rust. Spraying (throwing) rust removal is driven by a high-power motor to rotate the spraying (throwing) blades at high speed, so that steel sand, steel shots, iron wire segments, minerals and other abrasives are sprayed (throwing) on the surface of the steel pipe under the action of centrifugal force . Not only can rust, oxides and dirt be completely removed, but the steel pipe can also achieve the required uniform roughness under the action of violent impact and friction of abrasives. After spraying (throwing) to remove rust, it can not only expand the physical adsorption on the surface of the pipe, but also enhance the mechanical adhesion between the anti-corrosion layer and the surface of the pipe. Therefore, spraying (throwing) shot derusting is an ideal derusting method for pipeline corrosion. Generally speaking, shot blasting (sand) derusting is mainly used for pipe inner surface treatment, and shot blasting (sand) derusting is mainly used for pipe outer surface treatment.

3. Sand blasting to remove rust. A rust removal method that uses high-pressure air to bring out quartz sand and spray it to the surface of the component. The sources of quartz sand are: river sand, sea sand and artificial sand. The cost of sand is low and there are many sources, but it is very polluting to the environment; derusting is completely dependent on manual operation, and the surface roughness of the components after derusting is small, and it is difficult to meet the requirements of the friction coefficient. Sea sand should be desalted before use. The above two rust removal methods require the ambient humidity to be less than 85%.

4. Pickling and rust removal. Pickling rust removal is also called chemical rust removal. Its principle is to use the acid in the pickling solution to chemically react with metal oxides to dissolve the metal oxides and remove the rust and dirt on the steel surface. But pickling can't achieve or the surface roughness effect. And after pickling and rust removal, a lot of clean water must be cleaned and passivated; a lot of waste water, waste acid, and acid mist formed by it constitute environmental pollution. If it is not handled properly, it will cause over-corrosion of the metal surface and cause pitting. It is rarely used now.

5. Manual and power derusting. The tool is simple and easy to construct. However, the labor intensity is high, and the rust removal quality is poor. This method can only be used partially under the conditions that other methods do not have. For example, the trimming of individual components or some derusting treatment on the equipment site. The commonly used tools are: grinder, blade, wire brush, emery cloth, etc.