Seamless steel pipes are divided into two types: hot-rolled and cold-rolled (drawn) seamless steel pipes.
Hot rolled seamless steel pipes are divided into general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes,
stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes.
Cold rolled (drawn) seamless steel pipes are divided into general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, and other steel pipes, as well as carbon thin-walled steel pipes, alloy thin-walled steel pipes, Stainless thin-walled steel pipes, special-shaped steel pipes. The outer diameter of hot-rolled seamless pipe is generally greater than 32mm and the wall thickness is 2.5-75mm. The diameter of cold-rolled seamless pipe can be up to 6mm and the wall thickness can be up to 0.25mm. The outer diameter of thin-walled pipe can be up to 5mm and the wall thickness is less than 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling.
General seamless steel pipe: It is made of 10, 20, 30, 35, 45 and other high-quality carbon steels such as 16Mn, 5MnV and other low-alloy structural steels or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steels by hot rolling or cold rolling. Seamless pipes made of low carbon steel such as 10 and 20 are mainly used for fluid transportation pipelines. Seamless tubes made of medium carbon steel such as 45 and 40Cr are used to manufacture mechanical parts, such as stressed parts of automobiles and tractors. Generally, seamless steel pipes must be used for strength and flattening tests. Hot-rolled steel pipes are delivered in hot-rolled or heat-treated state; cold-rolled steel is delivered in heat-treated state.
1. Low and medium pressure boiler tubes: used to manufacture various low and medium pressure boilers, superheated steam tubes, boiling water tubes, water wall tubes and superheated steam tubes for locomotive boilers, large smoke tubes, small smoke tubes and arched brick tubes, etc. Use high-quality carbon structural steel hot-rolled or cold-rolled (dial) seamless steel pipe. It is mainly made of No. 10 and No. 20 steel. In addition to ensuring the chemical composition and mechanical properties, a hydraulic test, such as crimping, flaring, and flattening, is required. Hot-rolled products are delivered in hot-rolled state, and cold-rolled products are delivered in heat-treated state.
2. High-pressure boiler steel pipes: high-quality carbon structural steel, alloy structural steel and stainless heat-resistant steel seamless steel pipes mainly used to manufacture high-pressure and above steam boiler pipes. These boiler pipes are often under high temperature and high pressure. Work and pipes will also undergo oxidation and corrosion under the action of high-temperature flue gas and water vapor. Therefore, steel pipes are required to have high durability, high oxidation resistance, and good structural stability. The steel grades used are: high-quality carbon Plain structural steel grades are 20G, 20MnG, 25MnG; alloy structural steel grades 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, etc.; rust and heat-resistant steel commonly used 1Cr18Ni9, 1Cr18Ni11Nb high-pressure boiler tubes to ensure chemical composition and mechanical In addition to performance, water pressure test should be done one by one, and flaring and flattening tests should be done. The steel pipe is delivered in a heat-treated state. In addition, there are also certain requirements for the microstructure, grain size, and decarburized layer of the finished steel pipe.
3. Seamless steel pipes for geological drilling and oil drilling: use drilling rigs to drill wells for the exploration of underground rock structure, groundwater, oil, natural gas and mineral resources. Oil and natural gas exploitation is even more inseparable from well drilling. Seamless steel pipes for geological drilling are the main equipment for drilling, including core outer tubes, core inner tubes, casings, and drill pipes. Because drilling pipes need to be deep into the formation depth of several kilometers, the working conditions are extremely complicated. The drill pipe is subjected to stresses such as tension, compression, bending, torsion, and uneven impact load, and also subjected to mud and rock wear. Therefore, pipe materials are required It must have sufficient strength, hardness, wear resistance and impact toughness. The steel used for steel pipes is represented by "DZ" (Geological Chinese Pinyin prefix) plus a number one to represent the yield point of steel. Commonly used steel grades are 45MnB and 50Mn of DZ45; 40Mn2, 40Mn2Si of DZ50; 40Mn2Mo, 40MnVB of DZ55; 40MnMoB of DZ60, 27MnMoVB of DZ65. The steel pipes are delivered in a heat-treated state.
4. Petroleum cracking pipes: seamless pipes for furnace pipes, heat exchanger pipes and pipelines used in petroleum refineries. Commonly used high-quality carbon steel (10, 20), alloy (12CrMo, 15CrMo), heat-resistant steel (12Cr2Mo, 15Cr5Mo), stainless steel (1Cr18Ni9, 1Cr18Ni9Ti) manufacturing. In addition to the certified chemical composition and various mechanical properties of the steel pipe, it is also necessary to ensure the water pressure, flattening, flaring and other tests, as well as surface quality and non-destructive inspection. The steel pipe is delivered under heat treatment. Stainless steel pipe: Hot-rolled and cold-rolled stainless steel pipes of various stainless steels are widely used in petroleum and chemical equipment pipelines and stainless steel structural parts for various purposes. In addition to ensuring chemical composition and mechanical properties, they are used as steel pipes that can withstand fluid pressure. To ensure that the water pressure test is qualified. All kinds of special steel pipes shall be guaranteed according to the stipulated conditions.
Tips: ASTM A53 covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.
A53 Grade B Seamless is our most polar product under this specification and A53 pipe is commonly dual certified to A106 B Seamless pipe.
