The role of steel shot in surface treatment of steel pipes

　　With the development of the economy, steel pipes are increasingly used in various chemical substance transportation industries. The surface treatment of steel pipes is one of the key factors that determine the service life of transportation pipelines. In addition to the coating type, coating quality and construction environment, the surface treatment of the steel pipe also has a great influence on the life of the anti-corrosion layer. This is where steel shot and steel sand come in handy.

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

　　The abrasive can be selected according to the hardness of the steel pipe surface, the original rust degree, the required surface roughness, the coating type, etc. It is easier to achieve the ideal rust removal effect by using a mixed abrasive of steel sand and steel shot. Steel shot can strengthen the steel surface, while steel grit can etch the steel surface. Mixed abrasives of steel grit and steel shot. Usually the hardness of steel shot is 40-50HRC, and the hardness of steel grit is 50-60HRC. It can be used on various steel surfaces, even on C- and D-grade rusted steel surfaces, except for The rust effect is also very good.

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