Contact Us
Contact: Mrs.Yao
Contact: Mr.Zhou
Tel: +86-510-83831286
Fax: +86-0510-83831286
Address: Yaxi industrial Park, Luoshe Town, Wuxi City, Jiangsu
Home > Exhibition > Content
Uneven deformation of High precision cold drawn tubes can cause cracking
Jan 18, 2019

In the process of processing High precision cold drawn tubes, due to the influence of metal flow and deformation non-uniformity, it will have a certain adverse effect on its quality, mainly to generate additional stress. Due to the influence of geometric factors, the dimensional change of each layer in the process of emptying the steel pipe cannot damage the integrity of the steel pipe, and the layers must be mutually restricted.


Thus the inner layer will transmit a force to the outer layer and will increase the latter deformation, ie the outer layer of the High precision cold drawn tube will be subjected to additional tensile stress. On the contrary, the outer layer with a small deformation tendency is transmitted to the inner layer with a large deformation tendency, and its function is to reduce the deformation of the latter, that is, the inner layer will be subjected to additional compressive stress. These additional tensile and compressive stresses are balanced within the steel tube, with the largest additional tensile stress on the outer surface and the greatest additional compressive stress on the inner surface.


During the drawing of the High precision cold drawn tube, if the wall of the steel pipe is thicker and the diameter is reduced, the additional tensile stress of the outer surface layer is increased, and the outer surface is prone to transverse cracking. If the steel pipe itself is poorly plasticized or the hydrogen is brittle after pickling, the annealing does not completely eliminate the work hardening, and the existing surface cracks exist, the plasticity during the processing of the steel pipe is lowered, and the chance of the transverse crack on the outer surface increases. A tangential additional tensile stress is generated in the outer ring, and a large additional tangential tensile stress on the outer surface layer is a mechanical factor of the longitudinal

Previous: Hollow piston rod material and processing technology

Next: Analysis of the key points of hollow piston rod