standards:
API SPEC 5L - American Petroleum Institute standards
GB/T9711.2-- China's national standards
use:
for the oil and gas industry of oxygen, water, oil pipeline
The main production steel grades:
B, X42, X52, X60, X65, X70
Tolerance:
| steel types |
pipe outside diameter (D) |
pipe wall thickness (S) |
| tube |
pipe outside diameter (mm) |
allow deviation (mm) |
pipe outside diameter (mm) |
allow deviation (mm) |
| ≥ 60.3 and S <20 |
± 0.75% |
≤ 73.0 |
+15%, -12.5% |
| ≥ 60.3 and S ≥ 20 |
± 1.00% |
> 73.0 and S <20 |
+15%, -12.5% |
| |
|
> 73.0 and S ≥ 20 |
+17.5%, -10 |
mechanical properties:
| standards |
Grade |
tensile strength (MPa) |
yield strength (MPa) |
Yield Ratio |
elongation (%) |
0 ℃ impact energy
Akv (J) |
state heat |
| API SPEC 5L
GB/T9711.2 |
B |
≥ 415 |
245 ~ 440 |
≤ 0.80 |
22 |
≥ 40 |
normalizing |
| X42 |
≥ 415 |
290 ~ 440 |
≤ 0.80 |
21 |
≥ 40 |
normalizing |
| X52 |
≥ 460 |
360 ~ 510 |
≤ 0.85 |
20 |
≥ 40 |
normalizing |
| X60 |
≥ 520 |
415 ~ 565 |
≤ 0.85 |
18 |
≥ 40 |
normalizing |
| X65 |
≥ 535 |
450 ~ 570 |
≤ 0.90 |
18 |
≥ 40 |
quenching + tempering |
| X70 |
≥ 570 |
485 ~ 605 |
≤ 0.90 |
18 |
≥ 40 |
quenching + tempering |
chemical composition:
| standards |
Grade |
chemical composition (%) |
CEV (%) |
| C |
Si |
Mn |
P |
S |
V |
Nb |
Ti |
| API SPEC 5L
GB/T9711.2 |
B |
≤ 0.16 |
≤ 0.40 |
≤ 1.10 |
≤ 0.020 |
≤ 0.010 |
- |
- |
- |
≤ 0.42 |
| X42 |
≤ 0.17 |
≤ 0.40 |
≤ 1.20 |
≤ 0.020 |
≤ 0.010 |
≤ 0.05 |
≤ 0.05 |
≤ 0.04 |
≤ 0.42 |
| X52 |
≤ 0.20 |
≤ 0.45 |
≤ 1.60 |
≤ 0.020 |
≤ 0.010 |
≤ 0.10 |
≤ 0.05 |
≤ 0.04 |
≤ 0.45 |
| X60 |
≤ 0.21 |
≤ 0.45 |
≤ 1.60 |
≤ 0.020 |
≤ 0.010 |
≤ 0.15 |
≤ 0.05 |
≤ 0.04 |
agreement |
| X65 |
≤ 0.16 |
≤ 0.45 |
≤ 1.60 |
≤ 0.020 |
≤ 0.010 |
≤ 0.06 |
≤ 0.05 |
≤ 0.06 |
≤ 0.45 |
| X70 |
≤ 0.16 |
≤ 0.45 |
≤ 1.70 |
≤ 0.020 |
≤ 0.010 |
≤ 0.06 |
≤ 0.05 |
≤ 0.06 |
≤ 0.45 |
Note:
1.0.015% ≤ Altot <0.06%; N ≤ 0.012%; Al / N ≥ 2 / 1; Cu ≤ 0.25%; Ni ≤ 0.30%; Cr ≤ 0.30%; Mo ≤ 0.10%
2. V + Nb + Ti ≤ 0.15
3. X60, X65, X70 by consensus Mo ≤ 0.35%