LSAW Steel Pipe

　　Overview of two steel pipe processes 　　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 → Hydraulic test (inspection) → mark → storage. 　　Hot rolling (extrusion seamless steel pipe): round tube billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing diameter) → cooling → blank tube → straightening → water pressure Test (or flaw detection) → mark → into storage. 　　Detailed explanation of two steel pipe processes 　　The cold drawn steel pipe is made of hot-rolled steel coil as raw material, it's subjected to pickling to remove scale and then cold-rolled. The finished product is rolled hard roll. The cold work hardening caused by continuous cold deformation to make the strength and hardness of the rolled hard roll rise and tough. T...