The analysis of seamless steel tube is introduced as follows:

Seamless steel tube is divided into seamless steel tube and cold rolled (dial) seamless steel tube.

Hot rolled seamless steel tube, low, medium pressure boiler tube, high-pressure boiler tube, alloy steel tube, stainless steel tube, petroleum cracking pipe, geological steel tube and other steel pipe. Cold-rolled (dial) seamless steel tube in addition to general steel tube, low medium pressure boiler pipe, high pressure boiler tube, alloy steel, stainless steel pipe, oil cracking pipe, steel pipe, other include carbon thin wall steel tube, alloy thin wall steel pipes, thin-walled stainless steel tube, steel tube. Generally greater than 32 mm hot rolled seamless steel tube diameter, wall thickness 2.5 75 mm, cold rolled seamless steel tube can be to 6 mm in diameter, wall thickness to 0.25 mm, to 5 mm thin wall pipe diameter, wall thickness less than 0.25 mm, cold than hot rolled high dimensional accuracy.

Generally, seamless steel tube: it is made of low alloy steel or 40Cr, 30CrMnSi, 45mnb, 40MnB, etc., such as 10, 20, 30, 35, 45, etc. The seamless steel tubes made of low carbon steel, such as 10 and 20, are mainly used in the flow pipeline. 45. The seamless steel tubes made of carbon steel, such as 40Cr, are used to make mechanical parts, such as the mechanical parts of cars and tractors. Generally use seamless steel tube to ensure strength and flattening test. Hot rolled seamless steel tube is delivered in hot rolling state or heat treatment state; Cold rolled seamless steel tube is delivered in heat treatment.

Seamless steel pipe weight calculation formula: [] - wall thickness (diameter) * wall thickness * = 0.02466 kg/m (if the weight of per meter for smaller size and better quality seamless tube, must adopt the method of cold rolling, cold drawing or both combined. Cold rolling is usually done on a two-high rolling mill. The steel pipe is rolled in a circular groove composed of a circular hole and a non-moving conical top. Cold drawing is usually carried out on a single - chain or double - chain cold-drawing machine with 0.5 ~ 100T.

High quality carbon structural steel cold steel seamless steel tube, mainly used in steel production of 10 and 20 steel, except to ensure chemical composition and mechanical properties of water pressure test, roll edge, expansion, flattening and other experiments.

Generally use seamless steel tube to ensure strength and flattening test. The hot rolled steel tube is delivered in hot rolled state or heat treatment state; Cold rolled with heat treatment.

Low medium pressure boiler seamless steel pipe: used in the manufacture of all kinds of low intermediate pressure boiler superheated steam pipe, water pipe, water wall tube and locomotive boiler superheated steam pipe, pipes, small pipe and tube arch brick, etc. Seamless steel tube with high quality carbon structural steel or cold rolled. It is mainly used in steel production of no.10 and no.20 steel. Besides the chemical composition and mechanical properties, the water pressure test should be done, the edge, expansion and flattening test are performed. Hot rolled in hot rolled state, cold rolled (dial) for heat treatment.

High pressure boiler seamless steel pipe: mainly used in the manufacture of high pressure and over pressure steam boiler pipes, etc. With high quality carbon structural steel, alloy steel and stainless heat resistant steel seamless steel tube, these often under high temperature and high pressure boiler tube, tube in high temperature flue gas and steam will happen under the action of oxidation and corrosion, so the steel pipe with high rupture strength, high oxidation resistance, and have good organizational stability, using steel grade are: high quality carbon structural steel grade 20 g, 20 MNG, 25 MNG; Alloy structural steel no. 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, etc. Corrosion resistant steel is used in 1Cr18Ni9 and 1Cr18Ni11Nb high pressure boiler tube to ensure chemical composition and mechanical properties, the water pressure test should be done by root, which should be expanded and flattened. The steel tube shall be delivered in heat treatment. Moreover, the microstructure, grain size and decarburization layer of finished steel tube are also required.

Seamless steel pipes for geological drilling and oil drilling: drilling Wells for underground rock formations, groundwater, oil, natural gas and mineral resources. Oil and gas exploitation are more inseparable from drilling Wells. Seamless steel pipe is the main equipment for drilling and drilling with oil drilling, mainly including core tube, core tube, casing, drill pipe and so on. Due to the drilling pipe to go deep into the thousands of meters formation depth work, working conditions is very complex, drill pipe under pull, pressure, bending, torsion and uneven impact load stress, but also by mud, rocks and wear, therefore, requires tubing must have sufficient strength, hardness, wear resistance and impact toughness, steel pipe steel with "DZ" pinyin "(geology) plus number one on behalf of the steel yield point, said common steel grade DZ45 MNB 45, 50 mn; DZ50 40Mn2, 40Mn2Si; DZ55 40Mn2Mo, 40MnVB; DZ60 40MnMoB, DZ65 27MnMoVB. The steel tubes are delivered in heat treatment.

Seamless steel pipe for petroleum cracking: seamless tube for furnace tube, heat exchanger pipe and pipe for oil refinery. Common quality carbon steel (10, 20), alloy steel (12CrMo, 15CrMo), heat-resistant steel (12Cr2Mo, 15Cr5Mo), stainless steel (1Cr18Ni9, 1Cr18Ni9Ti) are manufactured. In addition to the chemical composition and mechanical properties of the steel tube, the test of hydraulic pressure, flattening and expansion, and surface quality and non-destructive testing shall be ensured. The steel tube is delivered under heat treatment. Stainless steel pipe: with all kinds of stainless steel hot rolling and cold rolling stainless steel tube, pipe is widely used in petroleum, chemical industry equipment and various USES of the stainless steel structural parts, in addition to ensure that the chemical composition and mechanical properties, all steel pipe is used as the fluid under pressure to keep the water pressure test. All kinds of special steel pipes shall be guaranteed according to the regulations.