High toughness steel material and method of producing steel pipes using same
US6958099B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2003 |
| Grant date | Oct 25, 2005 |
| Priority date | — |
| Expiry date | May 15, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/28
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel material and a steel pipe made by using the same are provided which are to be used in severe oil well environments. Such a highly tough oil well steel pipe can be produced by rolling the base material, quenching the rolling product from the austenite region and tempering the same so that the relationship between the content of Mo [Mo] in the carbides precipitated at austenite grain boundaries and the austenite grain size (according to ASTM E 112) can be defined by the formula (a) given below. In this manner, steel pipes suited for use even under oil well environments becoming more and more severe can be produced while satisfying the requirements that the cost should be rationalized, the productivity improved and energy saved.[Mo]≦exp(G−5)+5 (a)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.