GB/T 32970 Q245 Longitudinal Submerged-arc Welded Steel Pipe for High Pressure Service at High Temperatures, ASTM A691/A691M, Q245, Q345, 15Mo, 20Mo, 12CrMo, 15CrMo, 14Cr1Mo, 12Cr1MoV, 12Cr2Mo1, 12Cr5Mo

GB/T 32970 Longitudinal Submerged-arc Welded Steel Pipe for High Pressure Service at High Temperatures

Standard: GB/T 32970
Equivalent Standards: ASTM A691/A691M

Material: Q245
Equivalent Materials: P265GH, 1.0425, 0.25C

Chemistry Composition

C, %	Si, %	Mn, %	P, %	S, %	Cu, %	Cr, %	Ni, %	Mo, %	V, %
0.17-0.23	0.17-0.37	0.35-0.65	0.025 max	0.015 max	0.20 max	0.25 max	0.25 max	0.15 max	0.08 max

Mechanical Properties

Tensile Strength , MPa	Yield Strength, MPa	Elongation, %	Impact (KV2)/J	Hardness
410-550	245 min	24 min	40 (OD≥76mm & WT≥14mm)	HBW 120-160	HV 120-160

Outside Diameter & Tolerance

Hot Rolled	Outside Diameter, mm	Tolerance
	Outside Diameter, mm	Ordinary	Advanced
	OD＜57	±0.40mm	±0.30mm
	57≤OD≤325, WT≤35	±0.75%	±0.50%
	57≤OD≤325, WT>35	±1%	±0.75%
	325＜OD≤600	+1% or +5mm	-
	OD>600	+1% or +7mm	-
Cold Drawn	Outside Diameter, mm	Tolerance
	OD≤25.4	±0.15mm	-
	25.4＜OD≤40	±0.20mm	-
	40＜OD≤50	±0.25mm	-
	50＜OD≤60	±0.30mm	-
	OD>60	±0.50%	-

Wall thickness & Tolerance

Hot Rolled	Wall Thickness, mm	Tolerance
	Wall Thickness, mm	Ordinary	Advanced
	WT≤4.0	±0.45mm	±0.35mm
	4＜OD≤20	+12.5%/-10%	±10%
	WT>20, OD＜219	±10%	±7.5%
	WT>20, OD≥219	+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/T 32970 specifies the terms and definitions, order content, size, shape, weight and allowable deviations, technical requirements, test methods, inspection rules, packaging, marking and quality certificates of LSAW steel pipes for high-temperature and high-pressure pipelines. GB/T 32970 is applicable to carbon steel and alloy steel straight seam submerged arc welded steel pipes for high temperature and high pressure pipelines in petroleum refining and coal chemical industries.
GB/T 32970规定了高温高压管道用直缝埋弧焊接钢管的术语和定义、订货内容、尺寸、外形、重量及允许偏差、技术要求、试验方法、检验规则、包装、标志和质量证明书。GB/T 32970适用于石油炼化和煤化工高温高压管道用碳钢和合金钢直缝埋弧焊接钢管。

Manufacture: tubes to GB/T 32970 shall be manufactured by hot rolled or cold drawn.
Heat Treatment: the tubes shall be produced by heat treated as normalizing.
Inspection & Test: chemistry composition analysis, tension test, flattening test or bending test, flaring test, hardness test, impact test, grain size grade, decarburized layer of both inside & outside, macroscopic examination, non-metallic inclusions, microstructure, 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 32970, High Pressure Steel Pipe, Boiler Steel Pipe, Steam Boiler Pipe, Pipeline, Piping

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