Production process of specially-shaped pipe

Abstract

The invention discloses a production process of a specially-shaped pipe. The production process of the specially-shaped pipe comprises the following steps: selecting a pipe, grinding ends of the pipe, annealing for a first time, pickling with acid for a first time, washing for a first time, phosphatizing for a first time, washing for a second time, saponifying for a first time, cold drawing for a first time, annealing for a second time, pickling with acid for a second time, washing for a third time, phosphatizing for a second time, washing for a fourth time, saponifying for a second time, cold drawing for a second time, straightening and carrying out antirust treatment. The production process of the specially-shaped pipe is characterized by firstly cold drawing a billet pipe in inner and outer circular dies so as to reduce the outer diameter of the wall thickness of the billet pipe, so that the inner and outer surfaces of the billet pipe are more smooth; the quality during cold drawing for the second time is improved; grains in the billet pipe subjected to cold drawing for the first time are unevenly distributed in the presence of stress; through annealing, the grains in the billet pipe are evenly distributed and the stress is removed, so that the breakage of the billet pipe when the billet pipe is subjected to cold drawing for the second time is avoided.

Description

technical field [0001] The invention relates to the production field of special-shaped pipes, in particular to a production process of special-shaped pipes. Background technique [0002] Shaped pipe is the general term for seamless pipes with cross-sectional shapes other than round pipes. Shaped pipes are widely used in various structural parts. At present, cold drawing is a common production method for special-shaped pipes. However, using the current cold drawing process The size of the special-shaped tube produced is not accurate enough, and the rejection rate is high, so it cannot be used in fields with high precision requirements. Contents of the invention [0003] In view of the above problems, the present invention provides a cold drawing production process of special-shaped pipes with precise finished product size and low reject rate. [0004] The technical scheme adopted in the present invention is: [0005] A production process for special-shaped pipes, comprisi...

AI Technical Summary

Problems solved by technology

[0002] Special-shaped pipe is the general term for seamless pipes with cross-sectional shapes other than round pipes. Special-shaped pipes are widely used in various structural parts. At present, cold drawing is a common production method for special-shaped pipes. However, using the current cold drawing process The size of the special-shaped tubes produced is not accurate enough, the scrap rate is high, and it cannot be used in fields with high precision requirements