Seamless steel pipes are divided into hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes due to different manufacturing processes. Cold drawn (rolled) tubes are divided into round tubes and special-shaped tubes. Perforation is the most important forming process in the production of hot-rolled tubes, and its task is to perforate a solid billet into a hollow billet (capillary).

The shot blasting machine for the inner and outer walls of the seamless steel pipe is a cleaning machine that combines the inner and outer walls of the steel pipe. The outer surface of the seamless steel pipe is cleaned by shot blasting, and the inner surface is cleaned by shot blasting to remove the scale on the surface.

Both round pipes (seamless pipes and welded pipes) and square (rectangular) cross-sections have the characteristics of biaxial symmetry, section centroid and shear center coincidence. The circular tube and square tube section have the same section moment of inertia for each axis, which has outstanding advantages as a bending and compression member.

Precision seamless pipe is a high-precision steel pipe material processed by cold drawing or hot rolling. Due to the characteristics of no oxide layer on the inner and outer walls of the precision steel pipe, no leakage under high pressure, high precision, high finish, no deformation in cold bending, flaring, flattening and no cracks, etc. Therefore, it is mainly used to produce pneumatic or hydraulic components, such as cylinders or oil cylinders. It can be seamless pipe or welded pipe The chemical composition of precision steel pipe

The pre-finishing welding process technology is the most advanced tube-making process technology in the spiral submerged arc welded pipe (SSAW pipe). Its advantage is to effectively solve the problem of mutual interference between forming and welding, give full play to the respective advantages of forming and welding, and realize the organic combination of high-speed forming and low-speed welding.

There are mechanical, chemical and electrochemical methods for removing scale from stainless steel pipes. Due to the complexity of the scale composition of stainless steel pipes, it is not easy to remove the scale on the surface and make the surface highly clear and smooth. The removal of scale on stainless steel welded pipes generally takes two steps, one is pretreatment, and the other is ash removal.