The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1999
Filed:
Jul. 31, 1997
Harold A Sreshta, Houston, TX (US);
Eric F Drake, Pearland, TX (US);
Camco International, Inc., Houston, TX (US);
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.