In the steel pipe classification system, seamless steel pipes for low and medium pressure boilers, seamless steel pipes for high-pressure boilers, and seamless steel pipes for geological and petroleum drilling are three important products with clear technical requirements and specialized scenarios. The following will be introduced separately.
Seamless steel pipes for low and medium pressure boilers
This type of steel pipe is mainly used to manufacture various low and medium pressure boilers, superheated steam pipes, boiling water pipes, water-cooled wall pipes, as well as superheated steam pipes, large smoke pipes, small smoke pipes, and arch brick pipes for locomotive boilers.
The product is made of high-quality carbon structural steel through hot rolling or cold rolling (drawing) process, mainly using 10 # and 20 # steel for manufacturing. In addition to ensuring the chemical composition and mechanical properties, hydrostatic testing, as well as edge rolling, expansion, flattening, and other tests are also required. Hot rolled steel pipes are delivered in a hot-rolled state, while cold-rolled (drawn) steel pipes are delivered in a heat-treated state.
Seamless steel pipes for high-pressure boilers
Seamless steel pipes for high-pressure boilers are mainly used to manufacture high-pressure and higher pressure steam boiler pipelines and other equipment. The materials used include high-quality carbon structural steel, alloy structural steel, and stainless heat-resistant steel.
These boiler tubes are exposed to high temperature and high pressure environments for a long time, and the tubes will undergo oxidation and corrosion under the action of high-temperature flue gas and steam. Therefore, higher performance requirements have been put forward for steel pipes: high durability, high oxidation resistance, and good structural stability.
The commonly used steel grades are as follows:
High quality carbon structural steel: 20G, 20MnG, 25MnG
Alloy structural steel: 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, etc
Stainless heat-resistant steel: 1Cr18Ni9, 1Cr18Ni11Nb
In addition to ensuring the chemical composition and mechanical properties, high-pressure boiler tubes also need to undergo water pressure tests one by one, as well as expansion and flattening tests. Steel pipes are delivered in a heat-treated state. In addition, there are clear requirements for the microstructure, grain size, decarburization layer, etc. of finished steel pipes.
Seamless steel pipes for low and medium pressure boilers
This type of steel pipe is mainly used to manufacture various low and medium pressure boilers, superheated steam pipes, boiling water pipes, water-cooled wall pipes, as well as superheated steam pipes, large smoke pipes, small smoke pipes, and arch brick pipes for locomotive boilers.
The product is made of high-quality carbon structural steel through hot rolling or cold rolling (drawing) process, mainly using 10 # and 20 # steel for manufacturing. In addition to ensuring the chemical composition and mechanical properties, hydrostatic testing, as well as edge rolling, expansion, flattening, and other tests are also required. Hot rolled steel pipes are delivered in a hot-rolled state, while cold-rolled (drawn) steel pipes are delivered in a heat-treated state.
Seamless steel pipes for high-pressure boilers
Seamless steel pipes for high-pressure boilers are mainly used to manufacture high-pressure and higher pressure steam boiler pipelines and other equipment. The materials used include high-quality carbon structural steel, alloy structural steel, and stainless heat-resistant steel.
These boiler tubes are exposed to high temperature and high pressure environments for a long time, and the tubes will undergo oxidation and corrosion under the action of high-temperature flue gas and steam. Therefore, higher performance requirements have been put forward for steel pipes: high durability, high oxidation resistance, and good structural stability.
The commonly used steel grades are as follows:
High quality carbon structural steel: 20G, 20MnG, 25MnG
Alloy structural steel: 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, etc
Stainless heat-resistant steel: 1Cr18Ni9, 1Cr18Ni11Nb
In addition to ensuring the chemical composition and mechanical properties, high-pressure boiler tubes also need to undergo water pressure tests one by one, as well as expansion and flattening tests. Steel pipes are delivered in a heat-treated state. In addition, there are clear requirements for the microstructure, grain size, decarburization layer, etc. of finished steel pipes.