Hardmetal facing for earth boring drill bit
US5988302A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Jul 31, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1209
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel tooth rolling cutter earth boring drill bit includes a bit body with a threaded upper end for attachment to the end of a drill string, and a lower end including three legs extending downwardly from the bit body and with a rolling cutter rotatably mounted on each leg. A layer of wear resistant material is applied to a portion of each rolling cutter and comprises wear resistant particles in a substantially steel matrix. The steel matrix is integrally formed with the cutter in a rapid, solid state densification powder metallurgy (RSSDPM) process, and includes a duplex microstructure comprising from about 10 to 40 volume percent austenite and from about 60 to 90 volume percent martensite. The duplex microstructure may be achieved by incorporating a minor fraction of pure nickel and/or manganese powder in the powder mix used in the process, thereby providing nickel or manganese enrichment of the austenitic zones of the matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.