Material of boiler superheater tubes
 
Boiler superheater
The boiler superheater is the heating surface for heating saturated water steam separated from steam water to rated superheated steam.
 
Superheated steam temperature of boiler superheater
The temperature of superheated steam depends on factors such as the pressure of the boiler, the amount of evaporation, the high temperature resistance of the steel, and the price of fuel and steel. For power station boilers, a 4 MPa boiler is generally about 450 ° C; The boiler is 540 to 570 ° C. A few utility boilers also use higher superheated steam temperatures (even up to 650 ° C).
 
Material of boiler superheater tubes
Superheater tube wall metal bears the highest temperature in the pressured parts of the boiler. Therefore, high-temperature resistant high-quality low-carbon steel and various chromium-molybdenum alloy steel must be used. At the highest temperature, austenitic chromium-nickel stainless steel is sometimes used. .
If the temperature of the pipeline during the operation of the boiler exceeds the allowable temperature limit of the material's endurance strength, fatigue strength or surface oxidation, accidents such as pipe bursting will occur.
 

Materials for boiler superheater tubes from 100000 kW to ultra supercritical unit:
 
Carbon steel pipe:SA210 C

Standard	Grade	Application
ASME SA210	C	ASTM SA210 C tubes widely used in 300MW, 600MW and other large capacity power station boilers, with working temperature lower than 500 ℃, such as water wall, economizer, low-temperature superheater, etc.

 
 
Alloy steel tube:SA213 T11、SA213 T12、15CrMoG、SA213 T22、12Cr1MoVG、SA213 T23、SA213 T91、SA213 T92.

Standard	Grade	Application
ASME SA213	T11	ASME SA213 T11 Tubes forl Boiler, Superheater, and Heat-Exchanger.
	T12	ASME SA213 T12 Tubes are widely used in boiler superheater, reheater and other heating surface piping, header and main steam pipeline with working temperature not exceeding 550 ℃ of large capacity power station boiler, such as 300MW and 600MW.
	T22	ASME SA213 T22 Tubes are mainly used for superheater with wall temperature ≤ 580 ° C and steam pipe and header with wall temperature ≤ 540 ° C of large capacity power station boiler such as 300MW.,600MW. This kind of steel has been widely used in the United States, Japan and Europe. It has a long history in power plant operation and is a mature steel with stable running and good process performance.
	T23	ASME SA213 T23 Seamless Steel Tubes are mainly suitable for manufacturing superheater, reheater and water wall of large-scale utility boiler, and SA213 T23 Seamless Steel Tubes are better choice material for the main steam temperature below 620 ℃.
	T91	ASME SA213 T91 steel tubes are mainly used for manufacturing high temperature superheater, reheater and other pressure parts of subcritical and supercritical power plant boilers with metal wall temperature not exceeding 625 ° C, and also for pressure vessels and nuclear power high temperature pressure parts.
	T92	ASME SA213 T92 steel tubes have excellent performance, and the use temperature can reach 650 ℃. It can partially replace TP304H and TP347H austenitic stainless steel tubes to manufacture sub-critical, super-critical, or even super-supercritical power plant boilers with metal wall temperatures not exceeding 650 ° C, such as high-temperature superheaters, reheater tubes, and main steam tubes.
GB5310	15CrMoG	GB5310 15CrMoG Pipes are applied to high and medium pressure boiler steam pipes, headers, superheater pipes with wall temperature of 540 ° C, forgings and elastic elements with steam parameters of 510° C.
	12Cr1MoVG	GB5310 12Cr1MoVG alloy steel pipes are mainly used for boiler superheater, reheater and other heating surface piping systems with metal wall temperature not exceeding 580 ° C, boiler header and main steam pipe and other pressure parts with metal wall temperature not exceeding 565 ° C.

 
 
Stainless steel tube: SA213 TP347H、SA213 TP347HFG、SUPER304H、HR3C(SA213 TP310HCbN).

Standard	Grade	Application
ASME SA213	TP347H	SA213 TP347H Stainless tubes can be used in high temperature and high pressure environment, with the maximum operating temperature of 650℃ for pressure parts and 850℃ for oxidation resistant parts,and mainly used for making high temperature superheater, high temperature reheater, high temperature section of platen superheater and various high temperature and high pressure resistant pipe fittings and other components on large power generation boiler with subcritical and supercritical pressure parameters.
	TP347HFG	ASME SA213 TP347HFG Stainless steel tubes are mainly used to manufacture high temperature superheater, high temperature reheater, high temperature section of platen superheater and various high temperature and high pressure resistant pipe fittings of large-scale power generation boiler with supercritical pressure parameters.
	SUPER304H(S30432)	ASME SA213 SUPER304H(S30432) Stainless tubes are mainly used to manufacture superheater and reheater of ultra supercritical boiler with metal wall temperature not exceeding 700 ℃.
	HR3C(SA213 TP310HCbN)	HR3C steel has good high temperature corrosion resistance (steam oxidation resistance), and its allowable stress is greatly improved compared to ordinary SA213 TP310H steel. R3C(SA213 TP310HCbN) Tubes are mainly used in superheaters of ultra-supercritical boilers with harsh working conditions.