The advantages and disadvantages of billet quality are the primary factors to judge the quality of seamless tube. In order to ensure the reasonable progress of the piercing process and to obtain high quality seamless tubes, the geometrical size, microstructure and low rate surface state of the billet must be strictly required.
Seamless pipe
Excessive diameter or ellipse of billet will make the perforation condition worse, and the bending will occur because of excessive diameter compression.


The key internal structures are shrinkage and loose center, non-metallic inclusions, gas accumulation, etc. The strictness of this requirement varies with the use of seamless tubes and the type of steel.


The most important thing is the surface quality of the billet, because any defective urban seamless pipe products in the billet, often misaligned will lead to stress concentration, plastic deformation will deepen and prolong the difference.


In a word, in order to produce high quality seamless tube products, the good quality of tube is very important for the first step.