GB 9948 12Cr9Mo Seamless steel tubes for petroleum cracking, ASTM A335, ASTM A213, EN 10216-2, X11CrMo9-1, T9, P9, STBA26, 10, 20, 12CrMo, 15CrMo, 12Cr1Mo, 12Cr1MoV, 12Cr2Mo, 12Cr5Mo, 12Cr9Mo, 07Cr19Ni10, 07Cr18Ni11Nb, 07Cr19Ni11Ti, 022Cr17Ni12Mo2

GB 9948 Seamless steel tubes for petroleum cracking

Standard: GB 9948
Equivalent Standards: ASTM A335, ASTM A213, EN 10216-2, ISO 9329-2

Material: 12Cr9Mo
Equivalent Materials: X11CrMo9-1, T9, P9, STBA26

Chemistry Composition

C, %	Si, %	Mn, %	P, %	S, %	Cr, %	Ni, %	Cu, %	Mo, %
0.15 max	0.25-1.00	0.30-0.60	0.025 max	0.015 max	8.00-10.0	0.60 max	0.20 max	0.90-1.10

Mechanical Properties

	Tensile Strength , MPa	Yield Strength, MPa	Elongation, %	Impact (KV2)/J	Hardness (HBW)
12Cr9MoI	460-640	210 min	20 min	40 (OD≥76mm & WT≥14mm)	179 max
12Cr9MoNT	590-740	390 min	18 min	40 (OD≥76mm & WT≥14mm)	-

Outside Diameter & Tolerance

Hot Rolled	Outside Diameter, mm	Tolerance
	Outside Diameter, mm	Ordinary	Advanced
	OD≤54	±0.50mm	±0.30mm
	54＜OD≤325	±1%	±0.75%
	OD>325	±1%	-
Cold Drawn	Outside Diameter, mm	Tolerance
	Outside Diameter, mm	Ordinary	Advanced
	OD≤25.4	±0.15mm	-
	25.4＜OD≤40	±0.20mm	-
	40＜OD≤50	±0.25mm	-
	50＜OD≤60	±0.30mm	-
	OD>60	±0.75%	±0.50%

Wall thickness & Tolerance

Hot Rolled	Wall Thickness, mm	Tolerance
	Wall Thickness, mm	Ordinary	Advanced
	WT≤20	+15%/-10%	±10%
	WT>20	+12.5%/-10%	±10%
Cold Drawn	Wall Thickness, mm	Tolerance
	Wall Thickness, mm	Ordinary	Advanced
	WT≤3.0	±0.30mm	±0.20mm
	WT>3	±10%	±7.5%

GB 9948 specifies the classification, code, size, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of seamless steel tubes for petroleum cracking. GB 9948 is applicable to seamless steel tubes for furnace tubes, heat exchanger tubes and pressure piping for petrochemical industry.
GB 9948规定了石油裂化用无缝钢管的分类、代号、尺寸、外形、重量、技术要求、试验方法、检验规则、包装、标志和质量证明书。GB 9948适用于石油化工用炉管、热交换器管和压力管道用无缝钢管。

Manufacture: tubes to GB 9948 shall be manufactured by hot rolled or cold drawn.
Heat Treatment: the tubes shall be produced by heat treated, 12Cr5MoI fully annealing, 12Cr5MoNT normalizing & tempering.
Inspection & Test: chemistry composition analysis, tension test, flattening test or bending test, flaring test, hardness test (alloy & stainless), impact test, macroscopic examination, non-metallic inclusions, microstructure, intergranular corrosion test (stainless), NDT, surface inspection and dimension check.

Length: 4000mm; 6000mm; 9000mm; 12000mm; and so on.
Max developed length: 30 meters, also U bending, finning, studded process can be provided.
Option: shot blasting on the outside surface to remove mill scale, make the surface matte colour; surface polishing as preparation work done for further processing, for instance finning.

Keyword: GB T 9948, High Pressure Steel Pipe, Heat Exchanger Steel Tubes, Furnace Tubes, Piping

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