Seamless steel pipe specifications are expressed in millimeters of outer diameter * wall thickness.
Classification of seamless carbon steel pipe: seamless steel pipe is divided into two categories of hot-rolled and cold-rolled (dial) seamless steel pipe.
Hot rolled seamless steel pipe is divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking pipe, geological steel pipe and other steel pipe.
Cold rolled (dial) seamless steel pipe in addition to general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking pipe, other steel pipe, but also includes carbon thin-walled steel pipe, alloy thin-walled steel pipe, stainless thin-walled steel pipe, profiled steel pipe. Hot rolled seamless pipe outer diameter is generally greater than 32mm, wall thickness 2.5-75mm, cold rolled seamless steel pipe diameter can be up to 6mm, wall thickness can be up to 0.25mm, thin-walled pipe outer diameter can be up to 5mm, wall thickness of less than 0.25mm, cold rolled than hot rolled high dimensional accuracy.
General seamless carbon steel pipe: 10, 20, 30, 35, 45 and other high-quality carbon steel 16Mn, 5MnV and other low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steels made of hot-rolled or cold-rolled. 10, 20 and other low-carbon steel seamless pipe is mainly used in the fluid transportation pipeline. 45, 40Cr and other medium carbon steel Seamless pipes made of medium carbon steel such as 45, 40Cr are used to manufacture mechanical parts, such as automobiles, tractors, stress parts. General use of seamless steel pipe to ensure the strength and flattening test. Hot-rolled steel pipe to hot-rolled state or heat treatment state delivery; cold-rolled to heat treatment state delivery.
Low and medium pressure boiler seamless steel pipe: used in the manufacture of a variety of low and medium pressure boilers, superheated steam pipe, boiling water pipe, water-cooled wall pipe and locomotive boilers with superheated steam pipe, large smoke pipe, small smoke pipe and arch brick pipe. Hot-rolled or cold-rolled (dialed) seamless steel pipe made of high-quality carbon structural steel. Mainly with 10, 20 steel manufacturing, in addition to ensure that the chemical composition and mechanical properties to do hydrostatic test, crimping, flaring, flattening and other tests. Hot rolled to hot rolled state delivery, cold rolled (dial) to heat treatment state delivery.
High-pressure boiler steel pipe: mainly used in the manufacture of high-pressure and above pressure steam boiler piping and other high-quality carbon structural steel, alloy structural steel and stainless heat-resistant steel seamless steel pipe, these boiler tubes are often at high temperatures and high pressure work, the tube in the high temperature flue gases and the action of water vapor oxidation and corrosion will occur, so the steel pipe is required to have a high enduring strength, high oxidation resistance, and has a good organizational stability. Good organizational stability, the use of steel are: high-quality carbon structural steel steel number 20G, 20MnG, 25MnG; alloy structural steel steel steel number 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, etc.; rust-resistant and heat-resistant steel commonly used 1Cr18Ni9, 1Cr18Ni11Nb high-pressure boiler tube in addition to ensuring the chemical composition and mechanical properties, to do root by root hydraulic test, to be flared, flattened test. Steel pipe heat treatment state delivery. In addition, the finished steel pipe microstructure, grain size, decarburization layer also has certain requirements.
Geological drilling and oil drilling seamless steel pipe: in order to explore the underground rock structure, groundwater, oil, natural gas and mineral resources, the use of drilling rigs to drill wells. Oil, natural gas extraction is even more inseparable from drilling, geological drilling and oil drilling with seamless steel pipe is the main equipment for drilling, mainly including core outer pipe, core inner pipe, casing, drill pipe, etc.. Due to the drilling pipe to work deep into the depth of several thousand meters of stratum, the working conditions are extremely complex, the drill pipe is subjected to tensile, compressive, bending, torsion and unbalanced impact load and other stresses, but also by the mud, rock abrasion, so the requirements of the pipe must have sufficient strength, hardness, wear resistance and impact toughness, steel pipe with steel "DZ" (geology of the hanyu pinyin prefix) plus the number one on behalf of the yield point of steel, commonly used steel number DZ45 45MnB, 50Mn; DZ50 40Mn2, 40Mn2Si; DZ55 40Mn2Mo, 40MnVB; DZ60 40MnMoB, DZ65 27MnMoVB. steel pipe are delivered in heat treatment state.
Petroleum cracking pipe: used in petroleum refineries, furnace pipe, heat exchanger pipe and pipeline seamless pipe. Commonly used high-quality carbon steel (10, 20), alloy steel (12CrMo, 15CrMo), heat-resistant steel (12Cr2Mo, 15Cr5Mo), stainless steel (1Cr18Ni9, 1Cr18Ni9Ti) manufacturing. In addition to the chemical composition and various mechanical properties of steel pipe, but also to ensure that the water pressure, flattening, flaring and other tests, and surface quality and non-destructive testing. Steel pipe delivery in the heat treatment state. Stainless steel pipe: hot rolled with a variety of stainless steel, cold rolled stainless steel pipe, widely used in petroleum, chemical equipment, piping and various uses of stainless steel structural parts, in addition to the chemical composition and mechanical properties should be guaranteed, where used to withstand the pressure of fluids to ensure that the pipe is hydrostatic test pass. A variety of specialized steel pipe to ensure that the conditions in accordance with the provisions.