Seamless steel Pipe Manufacturing Process —Hot Piercing
Last week we received an order for seamless steel pipe with A335 P11, which will be used for Russian boiler renovation project. Seamless pipe is strongest among all pipe types as it has a homogeneous structure throughout pipe length.
Seamless tubes are made through a series of processes, such as heating, hot piercing, pickling phosphating, cold drawing, heat treatment, sand blasting, straightening, flaw detection, hydrostatic test, finished.
The picture above is the whole manufacturing process of seamless steel pipe. Now let’s learn more about hot piercing.
In mandrel mill pipe manufacturing process, steel billet is heated to high temperature in the rotary furnace. A cylindrical hollow, which is also known as mother hollow, is produced with the help of a rotary piercer and set of roller arrangement that keeps the piercer at the center of the billet. Outside diameter of piercer is approximately that of the inside diameter of the finished pipe. With the help, secondary roller arrangement outside diameter and thickness are achieved.
During hot piercing process, there is one unavoidable problem, that’s wall thickness deviation. Please refer to another article, no more details here.