The Type and Application of Seamless Steel Pipe
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.
A. Process overview
Hot rolling (extruded seamless steel pipe): billet → heating → piercing → three roll cross rolling/continuous rolling/extrusion → tube removal → sizing (or reducing) → cooling → billet tube → straightening → water pressure Test (Eddy current test) → mark → warehouse
Cold drawn (rolled) seamless steel pipe: billet → heating → piercing → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening → Water pressure test (Eddy current test) → mark → warehouse
B. Seamless steel pipes are divided into the following varieties due to their different application:
Seamless steel pipe for structure: Mainly used for general structure and mechanical structure.
Seamless steel pipe for conveying fluid: Mainly used in engineering and large equipment to transport fluid pipelines.
Seamless steel tubes for low and medium pressure boilers: Mainly used for pipelines for industrial boilers and domestic boilers to transport low and medium pressure fluids
Seamless steel pipe for high pressure boiler: Mainly used for high temperature and high pressure transmission fluid headers and pipelines in power stations and nuclear power plants
Carbon steel and carbon-manganese steel seamless steel pipes for ships:
Mainly used for Class I and II pressure pipes for ship boilers and superheaters, etc.
Seamless steel pipes for high-pressure fertilizer equipment: Mainly used for conveying high temperature and high pressure fluid pipelines on fertilizer equipment.
Seamless steel pipe for petroleum cracking:
Mainly used in boilers, heat exchangers and fluid pipelines of petroleum smelters.
Seamless steel tube for gas cylinder: Mainly used to produce various gas and hydraulic cylinders.
Hot rolled seamless steel pipe for hydraulic prop: Mainly used to make coal mine hydraulic supports, cylinders and columns, and other hydraulic cylinders and columns.
High pressure seamless steel pipe for diesel engine: Mainly used for high pressure oil pipe of diesel engine injection system. The steel pipe is generally cold drawn.
Cold drawn or cold rolled precision seamless steel tube: It is mainly used for steel pipes for mechanical structures and carbon pressure equipment that require high dimensional accuracy and good surface finish.
Cold drawn seamless steel pipe: It is mainly used to make various structural parts, and its materials are high-quality carbon structural steel and low-alloy structural steel.
Precision inner diameter seamless steel pipes for hydraulic and pneumatic cylinders: It is mainly used to make cold drawn or cold rolled seamless steel pipes with precise inner diameters for hydraulic and pneumatic cylinders.
Seamless stainless steel tubes for boilers and heat exchangers: Mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. of chemical enterprises. Used high-temperature, high-pressure, corrosion-resistant steel pipe.
Seamless stainless steel pipe for structure: It is mainly used for general structure (hotel and restaurant decoration) and mechanical structure of chemical enterprises, which are resistant to atmospheric and acid corrosion and have certain strength steel pipes.
Seamless stainless steel pipe for fluid transportation: Mainly used for pipelines that transport corrosive media.
Seamless steel pipe for automobile axle casing: It is mainly used to make high-quality carbon structural and alloy structural hot-rolled seamless steel pipes for automobile half-axle sleeves and axle tubes of drive axle housings.