Why there are quality defects on the surfaces of high precision cold drawn seamless steel pipe

High precision cold drawn seamless steel pipe is a new high-tech energy-saving product. The popularization and application of high precision cold drawn seamless steel pipe is very helpful to save steel, improve processing efficiency and save energy. High precision cold drawn seamless steel pipe has the characteristics of strict dimensional accuracy (tolerance range) of inner and outer diameter, good internal and external surface finish, roundness and straightness, and even wall thickness.

Causes of quality defects on the inner and outer surfaces of high precision cold drawn seamless steel pipe:
① It is caused by the surface defect or internal defect of cold drawn seamless steel pipe blank.
② During the production of high precision cold drawn seamless steel pipe, such as the design of rolling process parameters is not correct, the mold surface is not smooth, the lubrication conditions are not good, and the pass design and adjustment are not reasonable.

③ In the process of heating rolling, heat treatment and straightening of cold drawn seamless steel pipe blank, if excessive residual stress is produced due to improper heating temperature control, uneven deformation, unreasonable heating and cooling speed or too large straightening deformation, it may also cause surface crack of cold drawn seamless steel pipe.

There are many reasons for the defects in the production process of cold drawn seamless steel pipe, which have a great impact on the performance of cold drawn seamless steel pipe. Therefore, cold drawn seamless steel pipe manufacturers must avoid these situations in the production process.