The seamless cold drawn pipe manufacturing process is generally divided into the following two types:
Hot rolling (extrusion seamless steel pipe), cold drawn (rolled) seamless steel pipe
Note: The raw material of the seamless steel pipe is: round tube blank
Seamless stainless steel tube manufacturing process
Hot rolling (extrusion seamless steel pipe): round billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing diameter) → cooling → straightening → hydrostatic test (or Flaw detection) → mark → warehousing.
Cold drawn (rolled) seamless steel pipe: round tube billet → heating → perforation → head → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → water Pressure test (inspection) → mark → storage.