Seamless Steel Pipe Causes Oval

Seamless Steel Pipe Causes Oval

Seamless steel pipe oval is finished cross section oval. In the process of drawing the use of the die hole is oval-shaped extubation die or in the straightening of the seamless steel pipe at both ends of the excessive bending, straightening in the process of up and down movement, seamless steel pipe diameter is too large to push into Stuck, the tail of the steel pipe is too large, and the uneven distribution of the weight between the pair of straightening rollers will cause such defects. If the defect due to the die hole oval should replace the extubation die. If the seamless steel pipe ellipse is formed during the straightening process, the cause of the ellipse should be eliminated when straightening is eliminated.

Causes and Preventive Measures of Wall Thickness Tolerance of Seamless Steel Pipe

The main reason for the poor wall thickness of the seamless steel pipe is improperly mismatched, or the change in mold size due to wear. It is not accurate to estimate the amount of wall thickness in the wall after the wall is fixed. Before using the arc outer die and the conical mandrel, the mandrel is not properly adjusted before or after the short mandrel is drawn. In order to prevent the seamless steel pipe wall thickness tolerance, should be correct with the mold, the correct adjustment of the mandrel position, airway pass in the seamless steel pipe wall thickness changes should be estimated accurately.

Seamless steel pipe surface pits cause

Seamless steel pipe is the distribution of the surface of the steel pipe in the area of the local depression, the distribution of some cyclical, and some irregular. The production of the pits is due to the fact that the iron oxide skin or other hard dirt is pressed into the surface of the seamless steel pipe during drawing or straightening, or the original is present on the surface of the steel pipe. Measures to prevent the occurrence of pits is to carefully check the pipe material and remove the flaws and other defects, to keep the workplace, tools and lubricants clean, to prevent the oxidation of iron oxide and dirt on the surface of seamless steel pipe.