Application and development of 12Cr1MoVG steel-Boiler Tubes,Heat-Exchanger Tubes,Superheater Tubes,Supplier,Beite

Application and development of 12Cr1MoVG steel

Application and development of 12Cr1MoVG steel

12Cr1MoVG steel was developed by the Central Academy of ferrous metallurgy of the Soviet Union in the 1950s. It was developed from the original 12xm steel (0.5% Cr-Mo-V) to 12x1m (1% Cr-Mo-V) steel by increasing the Cr content. The chemical composition of 12Cr1MoVG steel is simple, the total alloy content is less than 2%, and it has excellent process and physical properties. At present, it has been listed in the seamless steel pipe standard for high pressure boiler in China (GB5310-2008). In the 1960s, China began to copy and put into semi industrial test. In the early 1970s, it was included in the standard yb529-70 of the Ministry of metallurgy, and in the 1980s, it was included in the national standard gb5310. Similar steel grades widely used abroad include ASTM a405 p24 (1% CrMoV, USA), bs3604 (0,5% CrMoV, l% CrMoV, UK), din13crmov42, 10crmosiv7 (Germany), etc.

The normalized 12Cr1MoVG steel has good oxidation resistance below 580 ℃, the average oxidation rate is 0.05mm/y based on the extrapolation calculation of experimental data about 4000H; the oxidation rate is relatively low at 600 ℃, the extrapolation calculation based on the test data of 1000-1500h, the oxidation rate is 0.13mm/y; the 12Cr1MoVG steel has good structural stability, after aging at 580 ℃ and 600 ℃ for different times The hardness and impact of 12Cr1MoVG steel have little change, no hot kneeling and aging embrittlement tendency, but pearlite spheroidization will occur when 12Cr1MoVG steel is used for a long time at 580 ℃. Although mild to moderate spheroidization has little effect on the endurance strength, the fully spheroidized structure will significantly reduce the thermal strength. In addition, the production and manufacturing process of 12Cr1MoVG steel is simple, with high safety and reliability.

At present, 12Cr1MoVG material is widely used in Superheater, header and main steam conduit of high pressure, ultra-high pressure and subcritical power station boilers at home and abroad. This steel has become one of the main materials of power plant and boiler in China's power industry.

At present, 12Cr1MoVG steel is mainly used in the following aspects:

(1)12Cr1MoVG steel pipe is mainly used for superheater pipe, air pipe, main steam pipe, reheater pipe and other parts of boiler equipment, especially in high-pressure and ultra-high-pressure boiler, 12Cr1MoVG low alloy heat-resistant steel is widely used.

(2)12Cr1MoVG steel is mainly used for the main shaft,] impeller, rotor, fastener (bolt and nut), cylinder, nozzle chamber, lubricating valve, diaphragm and some blade materials of steam turbine.

(3)12Cr1MoVG steel is mainly used to reduce the working temperature of rotor and blade in hot gas engine to about 550 ℃, so as to expand the application of low alloy heat-resistant steel in gas engine.

(4)12Cr1MoVG steel can be used to manufacture gas turbine rotor, impeller, fastener and other parts with working temperature below 570 ℃.

(5)12Cr1MoVG steel pipe is mainly used for manufacturing furnace pipe, heat exchanger and other heating surface pipes in chemical and petroleum equipment.

The brittle fracture of 12CrlMoVG occurs along the grain boundary during the long-term service at high temperature, which poses a serious threat to the service safety. In particular, under the action of nuclear radiation, high temperature stress and impact load, warship structural steel is easy to cause brittle dynamic fracture, which is lower than the working stress in service, endangering the safety and reliability of warship. Tempering embrittlement, creep embrittlement and grain boundary stress corrosion cracking are the main forms of grain boundary embrittlement.