Tube shell for manufacturing a seamless steel pipe and a method for its manufacture
US7260966B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2005 |
| Grant date | Aug 28, 2007 |
| Priority date | — |
| Expiry date | Dec 21, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S72/70
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A pierced shell of an austenitic stainless steel having a good inner surface condition is provided, and a means is established which can perform mass production on an industrial scale of a good quality seamless steel pipe of stainless steel. An austenitic stainless steel billet with a P content of at most 0.040% and an S content of at most 0.020% is pierced under conditions such that the pipe expansion ratio H (outer diameter of shell/diameter of billet to be worked) satisfies the following equation to obtain a tube shell of an austenitic stainless steel. {P(%)/(0.025×H−0.01)}2+{S(%)/(0.015×H−0.01)}2≦1. When manufacturing a seamless steel pipe of an austenitic stainless steel, the above-described shell is rolled to form a pipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.