National Standards Tube for Petroleum Cracking Standard GB9948 Application It is used for the seamless steel tubes for furnace, heat exchangers and pipeline in petroleum refining factories. Main Steel Tube Grades 10, 20, 12CrMo, 15CrMo, 1Cr2Mo, 1Cr5Mo, 1Cr19Ni9, 1Cr19Ni11Nb etc. Other grades can also be provided after consulting with customers. Chemical Composition

Grade	Chemical Composition %
	C	Si	Mn	P	S	Cr	Mo	Ni
10	0.07-0.14	0.17-0.37	0.35-0.65	≤0.035	≤0.035	≤0.15	/	≤0.25
20	0.17-0.24	0.17-0.37	0.35-0.65	≤0.035	≤0.035	≤0.25	/	≤0.25
12CrMo	0.08-0.15	0.17-0.37	0.40-0.70	≤0.035	≤0.035	0.40-0.70	0.40-0.55	≤0.30
15CrMo	0.12-0.18	0.17-0.37	0.40-0.70	≤0.035	≤0.035	0.80-1.10	0.40-0.55	≤0.30
1Cr2Mo	≤0.15	0.50-1.00	0.30-0.60	≤0.035	≤0.030	2.15-2.85	0.45-0.65	/
1Cr5Mo	≤0.15	≤0.50	≤0.60	≤0.035	≤0.030	4.00-6.00	0.45-0.60	≤0.60
1Cr19Ni9	0.04-0.10	≤1.00	≤2.00	≤0.035	≤0.030	18.00-20.00	/	8.00-11.00
1Cr19Ni11Nb	0.04-0.10	≤1.00	≤2.00	≤0.035	≤0.030	17.00-20.00	/	9.00-13.00

Mechanical Properties

Grade	Mechanical Properties
	Tensile Strength MPa	Yield Strength MPa	Elongation %	Impact Energy J
10	330-490	≥205	≥24	/
20	410-550	≥245	≥21	≥39
12CrMo	410-560	≥205	≥21	≥55
15CrMo	440-640	≥235	≥21	≥47
1Cr2Mo	≥390	≥175	≥22	≥92
1Cr5Mo	≥390	≥195	≥22	≥92
1Cr19Ni9	≥520	≥205	≥35	/
1Cr19Ni11Nb	≥520	≥205	≥35	/