Reasons for the internal straightness of Seamless precision tube

Seamless precision tube are widely used. General-purpose Seamless precision tube are rolled from ordinary carbon structural steel, low-alloy structural steel or alloy structural steel, and have the largest output. They are mainly used as pipelines or structural parts for conveying fluids.

According to different purposes, it can be supplied in three categories:

　A. Supply according to chemical composition and mechanical properties;

　B. According to mechanical properties;

　C, according to the water pressure test supply.

The internal straightness in the production process of Seamless precision tube is a defect that often occurs on automatic pipe rolling mills, and it is also a difficult problem to solve. In most cases, the straightness is slight, which will not make the precision seamless steel pipe a scrap; but sometimes it is deeper. When rolling aviation pipe and alloy precision seamless steel pipe, this kind of defect will bring great harm and must be paid attention to. 

The reason for the internal straightness defects in the production of Seamless precision tube is that there are uneven defects on the surface of the top of the rolled tube, such as the welding of the burnt oxide scale on the top and the wear of the top (a basic type of component failure) and the distortion of the top shape (deformation) Ground changes), etc., scratch the inner surface of the precision seamless steel pipe. Due to the characteristics of longitudinal rolling, the scratch is straight. So it is called inner straight. The inner straight is mainly produced in the reduced wall area. The depth of the inner straight is generally about 0.2 mm.