2024-11-22
Methods Of Manufacturing Steel Tubes And Pipes-ERW Steel Pipe
Billet-Heating-Mannesmann piercer-Elongator-Plug mill-Reeler-Reheating-SizerWhen a seamless pipe is made by rolling, the rolling method involves piercing the material while it is being rolled, and is suitable for mass production. The figure shows the manufacturing process used in the Mannesmann plug mill, which is a typical rolling process. The Mannesmann-type piercer reduces the material by rolls that are inclined obliquely to each other. When the round billet is rotated while being compressed in the diametric direction, the central part of the billet becomes loose, which makes it easy to pierce a hole through the center. This is called the Mannesmann effect. The pierced portion is expanded by the elongator, and the wall thickness is then thinned and elongated by the pug mill. The internal and external surfaces are smoothed by the reeler, and the final dimensional adjustments are made by the sizer.