Drill Bit Having Increased Resistance To Fatigue Cracking And Method Of Producing Same

Author:  Bramlett, Griffo, Dah-Ben Liang, Potticary
Source:  US Patent 2005/0252691A1
Doc ID:  2005138
Year of Publication:  2005
Abstract:  
ABSTRACT The present invention relates to a roller cone drill bit that includes a bit body adapted to be rotated about a longitudinal axis, where the bit body has at least one leg depending therefrom, wherein the leg comprises a treated portion that provides a residual compressive stress, and a roller cone rotably mounted on a journal. The treated portion treatment may comprise one selected from shot peening, laser-shock peening, and hammer peening. Further, the present invention relates to a method of manufacturing a roller cone drill bit that includes inducing a compressive stress, through plastic deformation, in at least a portion of at least one leg depending from a bit body. The inducing a compressive stress may comprise one selected from shot peening, laser-shock peening, and hammer peening.