

| 
 钢管种类  | 
 外径(D)  | 
 钢管壁厚(S)  | ||
| 
 钢管外径(mm)  | 
 允许偏差(mm)  | 
 钢管壁厚(mm)  | 
 允许偏差(mm)  | |
| 
 冷拔管  | 
 >30-50  | 
 ±0.3  | 
 ≤30  | 
 ±10%  | 
| 
 >50-219  | 
 ±0.8%  | |||
| 
 热轧管  | 
 >219  | 
 ±1.0%  | 
 >20  | 
 ±10%  | 
| 
 标准  | 
 牌号  | 
 抗拉强度(MPa)  | 
 屈服强度(MPa)  | 
 伸长率(%)  | 
| 
 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  | 
| 
 标准  | 
 牌号  | 
 化学成分(%)  | ||||
| 
 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  | |