The materials of seamless steel pipes are: ordinary and high-quality carbon structural steel (Q215-A～Q275-A and 10～50 steel), low alloy steel (09MnV, 16Mn, etc.), alloy steel, stainless acid-resistant steel, etc.

      Seamless steel pipes have a hollow section and are used in large quantities as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, steel pipe has a lighter weight when the bending and torsion strength is the same, and it is a kind of economical cross-section steel. Different seamless steel pipe materials have different uses.

      (1) Introduction of seamless steel pipe material: 　　

      GB/T8162-1999 (Seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative materials (brands): carbon steel 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.　　

      GB/T8163-1999 (Seamless steel pipe for conveying fluid). Mainly used in engineering and large-scale equipment to transport fluid pipelines. The representative material (brand) is 20, Q345, etc.　　

GB3087-1999 (Seamless steel tubes for low and medium pressure boilers). Mainly used in industrial boilers and domestic boilers to transport low and medium pressure fluid pipelines. Representative materials are 10 and 20 steel.　　

      GB5310-1995 (Seamless steel tubes for high-pressure boilers). Mainly used for high-temperature and high-pressure conveying fluid headers and pipelines on boilers in power plants and nuclear power plants. Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.　

      GB5312-1999 (Carbon steel and carbon-manganese steel seamless steel pipes for ships). Mainly used for I and II pressure pipes for marine boilers and superheaters. Representative materials are 360, 410, 460 steel grades, etc.　　

      GB1479-2000 (Seamless steel pipes for high-pressure fertilizer equipment). Mainly used for conveying high temperature and high pressure fluid pipelines on fertilizer equipment. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.　　

      GB9948-1988 (Seamless steel pipe for petroleum cracking). Mainly used in boilers, heat exchangers and fluid pipelines of petroleum smelters. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.　　

      GB18248-2000 (Seamless steel tubes for gas cylinders). Mainly used to make various gas and hydraulic cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.　　

      GB/T17396-1998 (Hot-rolled seamless steel pipes for hydraulic props). Mainly used to make coal mine hydraulic supports, cylinders and columns, and other hydraulic cylinders and columns. Its representative materials are 20, 45, 27SiMn and so on.　　

      GB3093-1986 (High-pressure seamless steel pipes for diesel engines). Mainly used for high pressure oil pipe of diesel engine injection system. The steel pipe is generally cold drawn, and its representative material is 20A.

      GB/T3639-1983 (cold drawn or cold rolled precision seamless steel pipe). It is mainly used for steel pipes for mechanical structures and carbon pressure equipment that require high dimensional accuracy and good surface finish. Its representative materials are 20, 45 steel, etc.　　

      GB/T3094-1986 (cold drawn seamless steel pipe special-shaped steel pipe). It is mainly used to make various structural parts and parts, and its materials are high-quality carbon structural steel and low-alloy structural steel.　　

      GB/T8713-1988 (Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders). Mainly used to make cold drawn or cold rolled seamless steel pipes with precise inner diameters for hydraulic and pneumatic cylinders. Its representative materials are 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. of chemical enterprises. Used high-temperature, high-pressure, corrosion-resistant steel pipe. Its representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.　　

      GB/T14975-1994 (Stainless steel seamless 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. Its representative materials are 0-3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.　　

      GB/T14976-1994 (Stainless steel seamless steel pipe for fluid transportation). Mainly used for pipelines that transport corrosive media. Representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti, etc.

      (2) The purpose of seamless steel pipe: 　　

      Buildings include more underground pipelines, underground water extraction when building buildings, and boiler hot water transportation.　　

      Mechanical processing, bearing sleeves, processing machinery accessories, etc.　　

      Electrical: gas transmission, water power generation fluid pipeline.　

      Anti-static pipes for wind power plants, etc.