Characteristics and process flow of cold drawn seamless steel pipe
Aug 13, 2021
As an important part of steel products, steel pipes are divided into two categories: seamless steel pipes (round billets) and welded steel pipes (slabs, strip billets) due to their different manufacturing processes and different shapes of billets used.
Seamless steel pipes are divided into hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes due to their different manufacturing processes. Cold drawn (rolled) tubes are divided into two types: round tubes and special-shaped tubes.
Process overview
Hot rolling (extruded seamless steel pipe): round tube billet → heating → piercing → three-roll cross rolling, continuous rolling or extrusion → tube removal → sizing (or reducing) → cooling → billet tube → straightening → water pressure Test (or flaw detection) → mark → warehousing.
Cold drawn (rolled) seamless steel pipe: round tube billet → heating → piercing → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening → Hydraulic test (flaw detection) → mark → warehousing.
