1. Cleaning
The surface of steel can be cleaned by solvent and emulsion to remove oil, grease, dust, lubricant and similar organic matter. But
JIS G3445 Cold Drawn Carbon Seamless Steel Pipe can not remove rust, oxide scale and flux on the surface of steel, so it is only used as auxiliary means in anticorrosion production.
2. Rust removal by tools.
The main use of wire brushes and other tools on the steel surface grinding, can remove loose or raised oxide scale, rust, welding slag and so on. Manual tool rust removal can reach Sa2, power tool rust removal can reach Sa3, if the steel surface adhered to a solid oxide scale, tool rust removal effect is not ideal, can not meet the requirements of anti-corrosion construction anchor line depth
3. Pickling
Generally, chemical and electrolytic methods are used for pickling treatment. Chemical pickling is only used for pipeline anticorrosion. Oxide scale, rust and old coatings can be removed. Sometimes it can be used as a re-treatment after sand blasting and rust removal. Although chemical cleaning can make the surface reach a certain degree of cleanliness and roughness, but its anchor lines shallow, and easy to cause environmental pollution.
4. Spray rust removal
Spray rust removal is a high-speed rotating spray blade driven by a high-power motor, so that steel sand, steel balls, wire sections, minerals and other abrasives under the action of centrifugal force on the surface of seamless steel pipe spray treatment, not only can thoroughly remove rust,oxide and dirt, but also under the action of abrasive impact and friction,seamless steel pipe can also be. Achieve uniform roughness required. After spraying rust removal, not only the physical adsorption on the surface of seamless steel pipe can be enlarged, but also the mechanical adhesion between the anticorrosive coating and the pipe surface can be enhanced. Therefore, spray descaling is an ideal way of rust removal for pipeline anticorrosion. Generally speaking, shot peening is mainly used for inner surface treatment of seamless steel pipe, while shot peening is mainly used for outer surface treatment of seamless steel pipe. Several problems should be paid attention to by spraying rust removal.
4.1 rust removal grade
The construction technology of epoxy, ethylene, phenolic and other anticorrosive coatings commonly used for seamless steel pipe generally requires the surface of seamless steel pipe to reach near white grade. Practice has proved that the scale, rust and other dirt can be removed by this kind of rust removal grade, and the depth of anchor lines can reach 40-100 micron, which fully meets the requirements of adhesion between anticorrosive coatings and seamless steel pipe.
