National Standards Boiler Tube Seamless Steel Tubes and Pipes for Boiler Standard GB5310 Application It is used for manufacturing heating-pipelines, containers, coal-saving devices, superheaters and reheaters of high pressure boilers. (P>9.8MPa, 450℃<T<650℃) Main Steel Tube Grades 20G, 20MnG, 15MoG, 15CrMoG, 12Cr2MoG, 12Cr1MoVG etc. Other grades can also be provided after consulting with customers. Chemical Composition

Standard	Grade	Chemical Composition %
		C	Si	Mn	P	S	Cr	Mo	V
GB5310	20G	0.17-0.24	0.17-0.37	0.35-0.65	≤0.030	≤0.030	/	/	/
	20MnG	0.17-0.24	0.17-0.37	0.70-1.00	≤0.030	≤0.030	/	/	/
	15MoG	0.12-0.20	0.17-0.37	0.40-0.80	≤0.030	≤0.030	/	0.25-0.35	/
	15CrMoG	0.12-0.18	0.17-0.37	0.40-0.70	≤0.030	≤0.030	0.80-1.10	0.40-0.55	/
	12Cr2MoG	0.08-0.15	≤0.50	0.40-0.70	≤0.030	≤0.030	2.00-2.50	0.90-1.20	/
	12Cr1MoVG	0.08-0.15	0.17-0.37	0.40-0.70	≤0.030	≤0.030	0.90-1.20	0.25-0.35	0.15-0.30

  Mechanical Properties

Standard	Grade	Mechanical Properties
		Tensile Strength MPa	Yield Strength MPa	Elongation %
GB5310	20G	≥415	≥245	≥24
	20MnG	410-550	≥240	≥22
	15MoG	450-600	≥270	≥22
	15CrMoG	440-640	≥235	≥21
	12Cr2MoG	450-600	≥280	≥20
	12Cr1MoVG	470-640	≥255	≥21