Types of carbon steel pipes:
Carbon steel pipes can be divided into seamless pipes and welded pipes (straight seam steel pipes, spiral pipes, high frequency welded steel pipes) according to the production method. Seamless steel pipes are made by hot rolling or cold drawing, and have high strength and tightness. Welded steel pipe is made by rolling steel plate or steel strip into a cylindrical shape, and then connecting the weld seams by resistance welding, submerged arc welding and other methods.
Carbon steel seamless pipes are divided into two types: 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.
1) Hot rolled (extruded) seamless steel pipe : round tube billet → heating → piercing → three-roll cross rolling, continuous rolling or extrusion → stripping → sizing (or reducing) → cooling → straightening → hydraulic test (or Flaw detection) → marking → storage
2) Cold drawn (rolled) seamless steel pipe: round tube blank→heating→piercing→heading→annealing→pickling→oiling (copper plating)→multi-pass cold drawing (cold rolling)→blank tube→heat treatment→straightening →hydrostatic test (flaw detection)→marking→storage
Classification of carbon steel:
Mild steel (also known as light steel):
The carbon content is usually between 0.04% and 0.30%. Low carbon steel has good ductility and toughness, can be processed hot and cold, and is easy to weld. Commonly used low carbon steels include Q195, Q215, Q235, etc.
Medium carbon steel:
The carbon content is usually between 0.30% and 0.60%. Medium carbon steel has high strength and hardness, but low ductility and toughness. Commonly used medium carbon steels include 45# steel, 40Cr and so on.
High Carbon Steel:
The carbon content is usually between 0.60% and 2.00%. High carbon steel has high strength and hardness, but low ductility and toughness, and poor weldability. Commonly used high carbon steels include 65Mn, T8, T10, etc.
Carbon steel pipes can be divided into seamless steel pipes and welded steel pipes according to the production method. Seamless steel pipes are made by hot rolling or cold drawing, and have high strength and tightness. Welded steel pipe is made by rolling steel plate or steel strip into a cylindrical shape, and then connecting the weld seams by resistance welding, submerged arc welding and other methods.
