Piercing method for manufacturing of seamless pipe
US7146836B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 2006 |
| Grant date | Dec 12, 2006 |
| Priority date | — |
| Expiry date | Jan 13, 2026 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21B19/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A piercing method for manufacturing a seamless pipe capable of suppressing the rotary forging effects and suppressing the redundant shear strain without excessive narrowing of the roll diameter is provided. This method is characterized by holding a feed angle β and a cross angle γ of main rolls in a range satisfying the following expressions (1) to (3), setting the relationship between outer diameter “d0” of the solid billet and the outer diameter “d” and thickness “t” of a hollow piece after piercing so as to satisfy the following expression (4), and further setting the relationship between inlet diameter D1 and outlet diameter D2 of the main roll with the above-mentioned “d0”, “d” and γ so as to satisfy the following expression (5)8°≦β≦20° (1)5°≦γ≦35° (2)15°≦β+γ≦50° (3)1.5≦−ψr/ψθ≦4.5 (4)(d/d0)/(0.75+0.025γ)≦D2/D1 (5)In the expression (4), ψr=1n(2t/d0) and ψθ=1n{2(d−t)/d0}.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.