Method of piercing in seamless tube manufacturing
US4470282A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1982 |
| Grant date | Sep 11, 1984 |
| Priority date | — |
| Expiry date | Jan 11, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21B19/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention relates to a method of rotary piercing in seamless tube manufacturing under a rotary piercing process, such as Mannesmann mandrel mill process. Rotary piercing operation is carried out by employing a rotary piercing mill having a pair of cone-shaped main rolls adapted to cooperate with a plug for rotary piercing and disc rolls disposed in opposed relation between the pair of main rolls and adapted to press hollow shell on the surface thereof. In this method of rotary piercing, the main rolls have feed and cross angles designed to meet certain conditions individually and in combination. The method makes it possible to carry out rotary piercing of less hot workable and/or extremely hard-to-work materials, that is, high-alloy steel billets, without surface torsional deformation and circumferential shear deformation. Thus, it is possible to manufacture high quality tubes of high-alloy steels free from outside seams and inside bore defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.