| Designation |
Symbol |
Description |
| 交货状态 |
代号 |
说明 |
| Cold finished (hard) |
BK（+C） |
Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation |
| 冷加工（硬） |
最后冷加工之后不进行热处理， 从而管子只可能进行很小的变形。 |
| Cold finished (Soft) |
BKW
（+LC） |
The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming (e.g. bending, expanding) |
| 冷加工（软） |
最后热处理之后进行小变形量的冷加工， 对钢管再加工时允许有限的冷变形（例如： 弯曲， 扩口） |
| Cold finished and stress-relieved |
BKS（+SR） |
Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree. |
| 冷加工后消除应力退火 |
最后冷加工后在Acl点以下进行退火， 以消除冷加工应力。 |
| Annealed |
GBK（+A） |
The last Cold forming process is followed by annealing in a controlled atmosphere. |
| 退火 |
最后冷加工之后，钢管在保护气体下进行完全退火。 |
| Normalized |
NBK（+N） |
The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere. |
| 正火 |
最后冷加工之后，钢管在保护气体下进行正火。 |
