1.Cleaning.
Solvents and emulsions are used to clean the surface of the steel to remove oil, grease, dust, lubricants, and similar organic matter, but it cannot remove rust, oxide scale, solder, etc. on the surface of the steel, so it is only used as an auxiliary means in anti-corrosion production.
2. Tools to remove rust.
Mainly use tools such as wire brushes to polish the steel surface, which can remove loose or warped oxide scale, rust, welding slag, etc. The rust removal of hand tools can reach the Sa2 level, and the rust removal of power tools can reach the Sa3 level. If the steel surface adheres to a firm oxide scale, the tool rust removal effect is not ideal, and the anchor pattern depth required for anti-corrosion construction cannot be reached.
3.Pickling.
Generally, two methods of chemical and electrolysis are used for pickling. Pipeline anti corrosion only uses chemical pickling, which can remove the oxide scale, rust, and old coatings. Sometimes it can be used as a reprocessing after sandblasting and rust removal. Although chemical cleaning can make the surface reach a certain degree of cleanliness and roughness, its anchor lines are shallow and easily pollute the environment.
4. Spray (throw) to remove rust.
Spraying (projecting) rust removal is to drive the spraying (projecting) blades to rotate at a high speed through a high-power motor, so that steel grit, steel shot, iron wire segments, minerals, and other abrasives are sprayed (projected) on the surface of the steel pipe under the action of centrifugal force. , Not only can completely remove rust, oxide, and dirt, but also the steel pipe can achieve the required uniform roughness under the action of the violent impact and friction of the abrasive.
After spraying (throwing) to remove the rust, it can not only expand the physical adsorption of the pipe surface but also enhance the mechanical adhesion of the anti-corrosion layer to the pipe surface. 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 surface treatment and shot blasting (sand) rust removal is mainly used for pipe outer surface treatment. Several problems should be paid attention to when using spray (throwing) to remove rust.
1. Derusting grade
2. Spray (throw) abrasive
3. The particle size and the ratio of abrasive
4. Derusting speed
5. Cleaning and preheating
Post time: Dec-11-2023