Oil country tubular goods excellent in collapse characteristics after expansion and method of production thereof
US7459033B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2003 |
| Grant date | Dec 2, 2008 |
| Priority date | — |
| Expiry date | Aug 7, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/909
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a method of production of oil country tubular goods having a small drop in collapse pressure after expansion and having a collapse pressure recovering by low temperature ageing at about 100° C. and oil country tubular goods obtained by this method of production.This method of production comprises hot rolling a steel slab having amounts of addition of C, Mn, P, S, Nb, Ti, Al, and N in specific ranges and having a balance of iron and unavoidable impurities and shaping the steel strip coiled at a temperature of not more than 300° C. as it is into a tube. Alternatively, it comprises heating steel pipe having amounts of addition of C, Mn, P, S, Nb, Ti, Al, and N in specific ranges and having a balance of iron and unavoidable impurities to a temperature of the Ac3 [° C.] to 1150° C., then cooling it in a range of 400 to 800° C. at a rate of 5 to 50° C./second.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.