Ultra-high toughness and high strength drill pipe and manufacturing process thereof
US10227828B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 2013 |
| Grant date | Mar 12, 2019 |
| Priority date | — |
| Expiry date | Jun 17, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/26
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention discloses a drill pipe having ultra-high toughness and high strength and comprising the following chemical elements in mass percentage: C: 0.24-0.30%, Si: 0.1-0.5%, Mn: 0.7-1.5%, Cr: 0.7-1.5%, Mo: 0.5-0.75%, V: 0.01-0.10%, Nb: 0.01-0.05%, P≤0.015%, S≤0.005%, and the balance of Fe and unavoidable impurities; and a process of manufacturing the drill pipe having ultra-high toughness and high strength, comprising: heating the drill pipe as a whole to 900-950° C.; subjecting the inner surface of the drill pipe to axial-flow water-spray cooling and the outer surface of the drill pipe to laminar-flow water-spray cooling while controlling the amount of the water sprayed at thickened ends of the drill pipe and that along the pipe body to be different from each other; and controlling the tempering temperature to be 650-675° C. The inventive drill pipe having ultra-high toughness and high strength has a longitudinal full-size impact toughness at −20° C. of at least 100 J and has a strength of 135 ksi.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.