The role of steel shot in the surface treatment of steel pipe

　　With the development of the economy, the use of steel pipes in various chemical substances transportation industries is becoming more and more extensive. The surface treatment of steel pipes is one of the key factors that determine the service life of transportation pipelines. In addition to the type of coating, coating quality and construction environment, the life of the anti-corrosion layer is also affected by the surface treatment of the steel pipe. This is where steel shot and steel grit come in handy.

　　Jet derusting is to drive the jet blades to rotate at a high speed through a high-power motor, so that abrasives such as steel sand and steel shot are sprayed (thrown) on the surface of the steel pipe under the action of centrifugal force, which can not only completely remove rust, oxides and dirt, but also Moreover, under the action of the violent impact and friction of the abrasive, the steel pipe can also achieve the required uniform roughness. After the steel pipe is sprayed (thrown) to remove rust, it not only expands the physical adsorption effect on the surface of the steel pipe, but also enhances the mechanical adhesion between the anti-corrosion layer and the surface of the pipe. Spray (throwing) rust removal is an ideal rust removal method for pipeline anticorrosion. Shot blasting (sand) derusting is mainly used for inner surface treatment of pipes, and shot blasting (sand) derusting is mainly used for outer surface treatment of pipes. Several problems should be paid attention to when using spray (throwing) rust removal.

　　The abrasive can be selected according to the hardness of the surface of the steel pipe, the degree of original rust, the required surface roughness, the type of coating, etc. It is easier to achieve the ideal rust removal effect by using the mixed abrasive of steel grit and steel shot. Steel shot can strengthen the steel surface, while steel grit can etch the steel surface. The mixed abrasive of steel grit and steel shot, usually the hardness of steel shot is 40~50HRC, and the hardness of steel grit is 50~60HRC, which can be used on various steel surfaces, even on steel surfaces with C-grade and D-grade corrosion. Rust works well too.

　　The surface treatment of the steel pipe seriously affects the service life of the pipe, and it is also the simplest and most direct treatment method. Therefore, it is necessary to strictly follow the requirements of the anti-corrosion layer specification for the surface of the steel pipe, and constantly explore, summarize and improve the surface treatment method of the steel pipe.