Description
Due to different manufacturing processes, it is divided into hot rolled (extruded) seamless steel pipe and cold drawn (rolled) seamless steel pipe. Cold drawn (rolled) pipe is divided into circular pipe and special-shaped pipe. a. Process flow overview Hot rolled (extruded) seamless steel pipe: round tube blank → heating → perforation → three roll cross rolling, continuous rolling or extrusion → pipe stripping → sizing (or reducing) → cooling → blank tube → straightening → hydrostatic test (or flaw detection) → marking → warehousing. Cold drawn (rolled) seamless steel pipe: round tube blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → hydrostatic test (flaw detection) → marking → warehousing. b. Seamless steel pipes are divided into the following varieties due to their different uses: GB / t8162-2008 (seamless steel tubes for structures). It is mainly used for general structure and mechanical structure. Its representative material (brand): carbon steel, 20 and 45 steel; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35crmo, 42CrMo P91, etc. GB / t8163-2008 (seamless steel pipe for fluid transportation). It is mainly used for conveying fluid pipelines on engineering and large equipment. The representative material (brand) is 20, Q345, etc. Gb3087-2008 (seamless steel tubes for low and medium pressure boilers). It is mainly used for pipelines conveying low and medium pressure fluids in industrial boilers and domestic boilers. The representative materials are 10 and 20 steel. GB5310-2008 (seamless steel pipe for high pressure boiler). It is mainly used for high temperature and high pressure transmission fluid headers and pipelines on boilers of power plants and nuclear power plants. The representative materials are 20g, 12Cr1MoVG, 15CrMoG, etc. Gb5312-1999 (carbon steel and carbon manganese steel seamless steel tubes for ships). It is mainly used for class I and II pressure pipes for marine boilers and superheaters. The representative materials are 360, 410 and 460 steel grades. GB6479-2000 (seamless steel pipe for high pressure chemical fertilizer equipment). It is mainly used for conveying high temperature and high pressure fluid pipeline on chemical fertilizer equipment. The representative materials are 20, 16Mn, 12CrMo, 12cr2mo, etc. GB9948-2006 (seamless steel pipe for petroleum cracking). It is mainly used for boilers, heat exchangers and fluid transmission pipelines in petroleum smelters. The representative materials are 20, 12CrMo, 1Cr5Mo, 1cr19ni11nb, etc. GB18248-2000 (seamless steel pipe for gas cylinder). It is mainly used for making various gas and hydraulic cylinders. The representative materials are 37Mn, 34Mn2V, 35CrMo, etc. GB / t17396-1998 (hot rolled seamless steel pipe for hydraulic prop). It is mainly used to make coal mine hydraulic support, cylinder and column, as well as other hydraulic cylinders and columns. The representative materials are 20, 45, 27SiMn, etc. Gb3093-1986 (high pressure seamless steel pipe for diesel engine). It is 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 with high dimensional accuracy and good surface finish for mechanical structure and carbon pressure equipment. Its representative materials are 20, 45 steel, etc. GB / t3094-1986 (cold drawn seamless steel pipe and special-shaped steel pipe). It is mainly used to make various structural parts and parts, which are made of high-quality carbon structural steel and low-alloy structural steel. GB / t8713-1988 (precision inner diameter seamless steel tubes for hydraulic and pneumatic cylinders). It is mainly used to make cold drawn or cold rolled seamless steel pipes with precise inner diameter 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). It is mainly used for boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. in chemical enterprises. High temperature, high pressure and corrosion-resistant steel pipes used. The representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc. GB / T14975-1994 (stainless steel seamless steel pipe for structure). It is mainly used for atmospheric and acid corrosion resistant steel pipes with certain strength for general structures (hotel and restaurant decoration) and mechanical structures of chemical enterprises. The representative materials are 0-3cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc. GB / t14976-1994 (stainless steel seamless steel pipe for fluid transportation). It is mainly used for pipelines conveying corrosive media. The representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti, etc. Yb / t5035-1993 (seamless steel pipe for automobile axle sleeve pipe). It is mainly used to make high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipe for automobile half shaft sleeve and drive axle housing shaft tube. The representative materials are 45, 45Mn2, 40Cr, 20crni3a, etc. API Spec 5ct-1999 (casing and tubing specification) is prepared and published by American Petroleum Institute (API) and is widely used all over the world. Among them: casing: the pipe extending into the drilling from the ground surface as the well wall lining, and the pipes are connected by coupling. The main materials are J55, N80, P110 and other steel grades, as well as C90, T95 and other steel grades resistant to hydrogen sulfide corrosion. Its low-grade steel (J55, N80) can be welded steel pipe. Oil pipe: the pipe inserted into the casing from the ground surface to the oil layer, and the pipes are connected by coupling or as a whole. Its function is to pump the oil from the reservoir to the ground through the oil pipe. The main materials are J55, N80, P110, and C90 resistant to hydrogen sulfide corrosion, which are prepared and released by the American Petroleum Institute and are common all over the world. Steel pipe weight formula: [(outer diameter wall thickness) * wall thickness] * 0.02466 = kg / M (weight per meter)Seamless steel pipe
The application field of 12Cr1MoVG alloy pipe is expanded to provide broader space for the development of the industry. According to the research of 12Cr1MoVG alloy pipe branch of China Special Steel Association, the demand for high-pressure 12Cr1MoVG alloy pipe length in China will increase by 10-12% annually in the future. Classification of 12Cr1MoVG alloy pipe.
The biggest advantage of 12Cr1MoVG alloy pipe is that it can be recycled 100%, which is in line with the national strategy of environmental protection, energy conservation and resource conservation. The national policy encourages the expansion of the application field of high-pressure 12Cr1MoVG alloy pipe.