Seamless steel tubes are divided into hot-rolled (extruded) seamless steel tubes and cold drawn (rolled) seamless steel tubes due to their different manufacturing processes. Cold drawn (rolled) tubes are divided into two types: round tubes and shaped tubes.
1. Process flow overview:
Hot-rolled seamless steel tube (extrusion seamless steel tube): round billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing diameter) → cooling → blank pipe → straightening →Hydraulic pressure test (or flaw detection)→marking→inbound
Cold drawn (rolled) seamless steel tube: 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
2. Seamless steel pipes are divided into the following varieties due to their different uses:
GB/T8162-1999 (seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative material (brand): carbon steel 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30- 35CrMo, 42CrMo, etc.
GB/T8163-1999 (seamless steel pipe for
conveying fluid). It is mainly used for conveying fluid pipelines on engineering and large equipment. Representative materials (brand) are 20, Q345, etc.
GB3087-1999 (seamless steel pipe for low and medium pressure boilers). It is mainly used for pipes for conveying low and medium pressure fluids in industrial boilers and domestic boilers. The representative material is 10, 20 steel.
GB5310-1995 (seamless steel tube for
high pressure boiler). It is mainly used for high temperature and high pressure conveying fluid gathering box and pipeline on power station and nuclear power plant boiler. Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.
GB5312-1999 (carbon steel and carbon-manganese steel seamless steel pipe for ships). It is mainly used for ship I boiler and superheater I, II pressure pipe, etc. The representative material is 360, 410, 460 steel grade.
GB1479-2000 (seamless steel pipe for high-pressure fertilizer equipment). It is mainly used for conveying high-temperature and high-pressure fluid pipelines on chemical fertilizer equipment. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.
GB9948-1988 (seamless steel pipe for petroleum cracking). It is mainly used in boilers, heat exchangers and pipelines for conveying fluids in petroleum smelters. Its representative materials are 20,12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.
GB18248-2000 (seamless steel pipe for gas cylinders). It is mainly used to make various gas and hydraulic cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.
GB/T17396-1998 (hot-rolled seamless steel pipe for hydraulic props). Mainly used for the production of coal mine hydraulic supports and cylinders, columns, and other hydraulic cylinders, columns. Its representative material is 20, 45, 27SiMn and so on.
GB3093-1986 (high-pressure seamless steel pipe for diesel engine). It is mainly used for high-pressure oil pipe of diesel engine injection system. Its steel pipe is generally cold drawn pipe, its representative material is 20A.
GB/T3639-1983 (cold drawn or cold rolled precision seamless steel pipe). Mainly used for mechanical structure, carbon pressure equipment, requires high dimensional accuracy, good surface finish steel. Its representative material is 20, 45 steel.
GB/T3094-1986 (cold drawn seamless steel pipe shaped steel pipe). Mainly used for the production of various structural parts and parts, the material is high quality carbon structural steel and low alloy structural steel.
GB/T8713-1988 (precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders). It is mainly used for the production of cold drawn or cold rolled seamless steel pipes with precision inner diameter for hydraulic and pneumatic cylinders. Its representative material is 20,45 Steel, etc.
GB13296-1991 (stainless steel seamless steel tubes for boilers and heat exchangers). Mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. for chemical enterprises. It is used for high temperature, high pressure and corrosion resistant steel pipes. Representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti and so on.
GB/T14975-1994 (Structural stainless steel seamless steel pipe). Mainly used for general structure (hotel, restaurant decoration) and chemical enterprise mechanical structure for atmospheric, acid corrosion and has a certain strength of the steel pipe. Its representative material is 0- 3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.
GB/T14976-1994 (stainless steel seamless steel pipe for fluid transportation). Mainly used for conveying corrosive medium pipes. Representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti and so on.
YB/T5035-1993
(Seamless steel pipe for automobile semi-axle casing). It is mainly used for the production of high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipe for automobile semi-axle casing and drive axle axle tube. Its representative material is 45,45Mn2 , 40Cr, 20CrNi3A and so on.
