Views: 4 Author: Site Editor Publish Time: 2022-07-11 Origin: Site
In the process of anti-corrosion construction of oil and gas pipelines, the surface treatment of large-diameter submerged arc steel pipes is a key factor in determining the service life of pipeline anti-corrosion, and it is the premise that the anti-corrosion layer and large-diameter submerged arc steel pipes can be firmly connected. To research by the research institute, the life of the anti-corrosion layer depends on factors such as coating type, coating, and construction conditions. According to the requirements for the surface of large-diameter submerged arc steel pipes, the surface treatment methods of submerged arc steel pipes have been improved from time to time.
1. Cleaning. Use solvents and emulsions to clean the surface of the steel to remove oil, grease, dust, lubricants, and similar organic substances, but it cannot remove rust, oxide scale, welding flux, etc. on the surface of the steel, so it is only used as an auxiliary in defense work. method, but also a simple maintenance method.
2. Pickling. Generally, two methods of chemical and electrolysis are used for pickling treatment. Pipeline anti-corrosion only uses chemical pickling, which can remove oxide scale, rust, and old coating. Sometimes it can be used for reprocessing after sandblasting and rust removal. Although chemical cleaning can make the surface reach a certain degree of cleanliness and roughness, its anchor pattern is shallow and easily pollutes the surrounding environment, Meide Steel Control Manufacturing Co., Ltd. does not recommend this method.
3. Derusting things. To use a wire brush and other tools to polish the surface of the steel, you can remove loose oxide scales, 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 surface of the steel adheres to a strong iron oxide scale, the rust removal results of the tools will not be considered, and the depth of the anchor pattern required by the anti-corrosion construction will not be met. It is a kind of Compared with the original rust removal method.
4. Radiation rust removal. Radiation rust removal is to drive the radiation blade to rotate at a high speed through a high-power motor so that the abrasives such as steel shot, steel sand, iron wire, and minerals are radiated to the surface of the submerged arc steel pipe under the strong centrifugal force of the motor, which can not only remove oxides, Rust and dirt, and the submerged arc steel pipe can reach the required average roughness under the effect of the abrasive impact and friction force. After radiation rust removal, it can not only expand the physical adsorption effect of the pipe surface but also strengthen the mechanical adhesion effect between the anti-corrosion layer and the pipe surface. Therefore, radiation rust removal is an ideal rust removal method for pipeline corrosion protection. Generally speaking, shot blasting and rust removal should be used for the inner and outer surface treatment of pipes, and shot blasting and rust removal should be used for surface treatment of submerged arc steel pipes.