GB 18248 gas cylinder tube
This standard is applicable to the manufacture of seamless steel pipes for gas cylinders and accumulator shells. Mainly supply 37Mn gas cylinder tubes, 30CrMo, 35CrMo, 34CrMo4 seamless steel pipes for gas cylinder oil pipes.
Standard: GB 18248
Equivalent Standards: JIS G3429, EN 10297-1, ASTM A372, EN 1964-1, EN ISO 11120, ISO 11439, ISO 9809-1, JIS B8230, JIS B8241
Brand: 37Mn, 34Mn2V, 30CrMo, 35CrMo, 34CrMo4, 30CrMnSiA
Outside diameter: 48 - 711 mm
Weight: 3.1 - 38mm
Length: 4-12m
Delivery status: not heat treated, quenched and tempered + quenched and tempered, normalized + tempered
GB 18248 specifies the size, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality certificates of seamless steel pipes for gas cylinders and accumulator shells. GB 18248 is suitable for manufacturing seamless steel pipes for gas cylinders and accumulator casings.
Manufacturing: Pipes according to GB/T 6479 should be manufactured by hot rolling or cold drawing.
Heat treatment: Pipes should be produced through heat treatment, WT≤30mm normalizing + tempering, WT>30mm quenching and tempering or normalizing + tempering.
Inspection and testing: chemical composition analysis, tensile test, flattening test, expansion test, impact test, macroscopic inspection, non-metallic inclusions, non-destructive testing, surface inspection, dimensional inspection.
Length: 4000mm; 6000mm; 9000mm; 12000mm; etc.
Maximum unfolded length: 30 meters. U-bend, fin, and nailing processes are also available.
Options: External surface shot blasting to remove scale and matt surface; surface polishing as preparation for further processing (e.g. fin trimming).
| Chemistry Composition |
|
C, %
|
Si, %
|
Mn, %
|
P, %
|
S, %
|
Cr, %
|
Ni, %
|
Cu, %
|
Mo, %
|
|
0.08-0.15
|
0.50 max
|
0.40-0.60
|
0.025 max
|
0.015 max
|
2.00-2.50
|
0.30 max
|
0.20 max
|
0.90-1.13
|
|
| Mechanical Properties |
|
Tensile Strength , MPa
|
Yield Strength, MPa
|
Elongation, %
|
Impact (KV2)/J at 20℃
|
|
450-600
|
280 min
|
20 min
|
40 (OD≥76mm & WT≥6.5mm)
|
|
| Outside Diameter & Tolerance |
|
Hot Rolled
|
Outside Diameter, mm
|
Tolerance
|
|
OD≤159
|
+1% or +0.50mm
|
|
OD>159
|
|
Cold Drawn
|
Outside Diameter, mm
|
Tolerance
|
|
Ordinary
|
Advanced
|
|
OD≤30
|
±0.20mm
|
±0.15mm
|
|
30＜OD≤50
|
±0.30mm
|
±0.25mm
|
|
OD>50
|
±0.50%
|
±0.50%
|
|
| Wall thickness & Tolerance |
|
Hot Rolled
|
Outside Diameter, mm
|
Tolerance
|
|
OD≤159
|
+12.5%/-10% or +0.50mm/-0.40mm
|
|
OD>159, WT/OD≤0.05
|
+15%/-10%
|
|
OD>159, 0.05＜WT/OD≤0.10
|
+12.5%/-10%
|
|
OD>159, WT/OD>0.10
|
±10%
|
|
Cold Drawn
|
Wall Thickness, mm
|
Tolerance
|
|
Ordinary
|
Advanced
|
|
WT≤2.0
|
+12.5%/-10%
|
±10%
|
|
WT>2.0
|
±10%
|
±7.5%
|
|
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