The delivery status of steel pipe (BK, BKW, BKS, GBK, NBK)
BK, BKW, BKS, GBK, NBK
Designation
|
Symbol
|
Description
|
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
|
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)
|
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.
|
Annealed
|
GBK（+A）
|
The last Cold forming process is followed by annealing in a controlled atmosphere.
|
Normalized
|
NBK（+N）
|
The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.
|
Nperuagse-1995 Ryan Black https://wakelet.com/wake/BoBzbzYSWhN60Ul0Bc4uP
回复删除cuedigholo
I know BKS, our hydraulic cylinder tube is made of seamless cold drawn tube of BKS heat treatment, but it seems seldom people uses BKW condition tubes?
回复删除