GB5310-2008 Grade 20G 12Cr1MoVG High Pressure Boiler Seamless Steel Pipe

Standard No： GB 5310-2008 Seamless steel tubes and pipes for high pressure boiler

1.GB5310 20G seamless steel tube for high-pressure boiler.

20G steel pipe is GB/5310 national standard steel number (foreign corresponding brand: German ST45.8, Japanese STB42, United States SA106B), for the most commonly used steel tube steel tube, chemical composition and mechanical properties are basically the same as the 20 plate. The steel has certain strength at room temperature and high temperature, low carbon content, good plasticity and toughness, and its cold and hot forming and welding properties are good.

Used for

20G steel pipes are mainly used for manufacturing high-pressure and higher parameter boiler tubes, low-temperature superheater, reheater, economizer and water wall.

Chemical composition of 20G (%)
C	Si	Mn	P	S
0.17~0.24	0.17~0.37	0.35~0.65	≤0.040	≤0.040

Mechanical properties of 20G
Yield strength	Tensile strength	Elongation	Impact	Hardness
≥250 Mpa	≥420MPa	≥25%	≥55%	HBS 156

GB5310 Grade 20G High Pressure Boiler Tube

2.GB5310 12Cr1MoVG Seamless steel tubes and pipes for high pressure boiler

12Cr1MoVG alloy steel pipe is used mainly after normalizing and tempering at high temperature to make the superheated pipe, pipe and snake tube at the working temperature of no more than 570~585 C in the high pressure equipment.

chemical composition 12Cr1MoVG
C	Si	Mn	Cr	Mo	V
0.08~0.15	0.17~0.37	0.40~0.70	0.90~1.2	0.25~0.35	0.15~0.30

mechanical properties 12Cr1MoVG
Tensile strength	Yield strength	Elongation	Impact	Hardness
≥490 Mpa	≥245Mpa	≥22	≥71	HB≤179

12Cr1MoVG alloy steel tube has higher oxidation resistance and thermal strength. The creep limit and the lasting strength of the steel are very close, and the steel has high plasticity under the condition of persistent stretching; the steel has good technological and weldability, but it needs to be preheated to 300 C before welding, and the stress treatment should be removed after the welding.