Paper: SHOT PEENING SUCKER RODS TO PROLONG FATIGUE LIFE

Shot peening has been utilized for many years in a variety of industries as a surface conditioning process for metals. When properly performed, shot peening imparts beneficial residual compression stresses to the surface and subsurface of a metal which enhances the fatigue resistance and corrosion tolerance properties. Shot peening is primarily used on components that operate in cyclic loading environments. Since sucker rods are subjected to alternating loads, shot peening should prove to be a viable method of retarding the effects of cyclic fatigue, thereby extending the service life of the rod. This paper will encompass: the shot peening method, effects, control, and benefits, shot peening vs. shot cleaning, residual stress measurement test results, high cycle rotational bending fatigue test results, testing of peened vs. non-peened new sucker rods, testing of shot peened vs. shot cleaned used rods, and testing of single peened vs. dual peened new rods to compare different peening processes and formulae.