Shot Peening Process

Author:  Robert A. Clay
Source:  US Patent 4,100,782
Doc ID:  1976049
Year of Publication:  1976
Abstract:  
A shot peening process is provided for treating elongated oil well sucker rods, drill pipes and the like. In accordance with the process of the invention, the rods or pipes are passed through appropriate shot peening equipment along an accurate path, and each rod or pipe is simultaneously rotated about its longitudinal axis. This action causes the rods or pipes to be flexed during the shot peening action. The effect of the flexing is to set the inner fibers of the rods or pipes under compression, thereby extending the fatigue resistance of the treated rods.