What's the production process of seamless steel pipe?

Production process of seamless steel pipe

Cold-drawn (rolled) seamless steel pipe in seamless steel pipe plant: round pipe blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multiple cold drawing (cold rolling) → billet pipe → heat treatment → Straightening → Hydraulic Test (Flaw Detection) → Marking → Storage

Hot-rolled seamless pipe in seamless steel pipe plant: round pipe billet → heating → perforation → three-roll diagonal rolling, continuous rolling or extrusion → stripping → sizing (or reduction) → cooling → straightening → water Pressure test (or flaw detection) → mark → storage

There are two types of seamless steel tubes: hot rolled and cold rolled (dial) seamless steel tubes. Hot rolled seamless steel pipe is divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking pipe, geological steel pipe and other steel pipes.

Cold rolled seamless steel pipes in seamless steel pipe plants include general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, and other steel pipes, as well as carbon thin wall steel pipes and alloys. Thin-walled steel pipe, stainless thin-walled steel pipe, special-shaped steel pipe. Large-diameter thick-walled steel pipe plants generally have an outer diameter of hot-rolled seamless pipes greater than 32mm and wall thicknesses of 2.5-75mm. The diameter of cold-rolled seamless steel pipes can reach 6mm, the wall thickness can reach 0.25mm, and the outer diameter of thin-walled pipes can reach 5mm. Thickness is less than 0.25mm, cold rolling has higher dimensional accuracy than hot rolling.