Method of piercing and manufacturing seamless tubes
US4827750A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Mar 25, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21B19/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In a method of manufacturing seamless tubes according to the present invention, piercing from a solid billet can be accomplished through one pass by means of a piercing mill ao the present invention, piercing from a solid billet can be accomplished through one pass by means of a piercing mill at the piercing ratio above 4.0 or the expansion ratio above 1.15, or the wall thickness/outside diameter ratio below 6.5%, and the piercing mill having cone-shaped rolls is used with its feed angle .beta. and cross angle .gamma. satisfying the following relations, PA1 8.degree..ltoreq..beta..ltoreq.20.degree. PA1 5.degree..ltoreq..gamma..ltoreq.35.degree. PA1 15.degree..ltoreq..beta.+.gamma..ltoreq.50.degree. and the solid billet diameter d.sub.o, outside diameter d and wall thickness t of a hollow shell after piercing satisfying a prescribed condition for realization, thereby manufacturing equipments can be largely simplified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.