Standard:GB9948-1988
Application: For manufacturing of furnace tubes, heat exchangers and pipelines in refineries
Tolerance on Dimensions
Pipe Types
| Pipe Size (mm)
| Tolerances
|
Hot Rolled
| OD | ≤159
| ±1.0%
|
>159
| ±1.20%
|
| WT | ≤20
| ±12.5%
|
>20
| ±10.0%
|
Cold Drawn
| OD | ≤30
| ±0.20mm
|
30-50
| ±0.30mm
|
>50
| ±0.8%
|
| WT | ≤3
| +12% -10%
|
>3
| ±10%
|
Chemical composition and mechanical properties
| Grade | Chemical Composition
| Mechanical Properties
|
C
| Mn
| Si
| Cr
| Mo
| Ni
| S | P | Tensile Strength(Mpa)
| Yield Strength(Mpa)
| Elongation(%)
|
10
| 0.07-0.14
| 0.35-0.65
| 0.17-0.37
| ≤0.15
| - | ≤0.25
| ≤0.035
| ≤0.035
| 330-490
| ≥205
| ≥24
|
| 20 | 0.17-0.24
| 0.35-0.65
| 0.17-0.37
| ≤0.25
| - | ≤0.25
| ≤0.035
| ≤0.035
| 410-550
| ≥245
| ≥21
|
12CrMo
| 0.08-0.15
| 0.40-0.70
| 0.17-0.37
| 0.40-0.70
| 0.40-0.55
| ≤0.30
| ≤0.035
| ≤0.035
| 410-560
| ≥205
| ≥21
|
15CrMo
| 0.12-0.18
| 0.40-0.70
| 0.17-0.37
| 0.80-1.10
| 0.40-0.55
| ≤0.30
| ≤0.035
| ≤0.035
| 440-640
| ≥235
| ≥21
|
1Cr2Mo
| ≤0.15
| 0.30-0.60
| 0.50-1.00
| 2.15-2.85
| 0.40-0.65
| - | ≤0.035
| ≤0.035
| ≥390
| ≥175
| ≥22
|
1Cr5Mo
| ≤0.15
| ≤0.60
| ≤0.60
| 4.00-6.00
| 0.45-0.60
| ≤0.60
| ≤0.035
| ≤0.035
| ≥390
| ≥195
| ≥22 |
