鋼管種類 | 外徑(D) | 鋼管壁厚(S) | ||
冷拔管 | 鋼管外徑(mm) | 允許偏差(mm) | 鋼管壁厚(mm) | 允許偏差(mm) |
>30~50 | ±0.3 | ≤30 | ±10% | |
>50~219 | ±0.8% | |||
熱軋管 | >219 | ±1.0% | >20 | ±10% |
標準 | 牌號 | 抗拉強度(MPa) | 屈服強度(MPa) | 伸長率(%) |
GB/T5312 | 320 | 320~410 | ≥195 | ≥25 |
360 | 360~480 | ≥215 | ≥24 | |
410 | 410~530 | ≥235 | ≥22 | |
460 | 460~580 | ≥265 | ≥21 | |
490 | 490~610 | ≥285 | ≥21 |
標準 | 牌號 | 化學成分(%) | ||||
C | Si | Mn | P | S | ||
GB/T5312 | 320 | ≤0.16 | ≤0.35 | 0.40~0.70 | ≤0.035 | ≤0.035 |
360 | ≤0.17 | ≤0.35 | 0.40~0.80 | ≤0.035 | ≤0.035 | |
410 | ≤0.21 | ≤0.35 | 0.40~1.20 | ≤0.035 | ≤0.035 | |
460 | ≤0.22 | ≤0.35 | 0.80~1.40 | ≤0.035 | ≤0.030 | |
490 | ≤0.23 | ≤0.35 | 0.80~1.50 | ≤0.035 | ≤0.030 |