The Story Of Shot Peening

Author:  Leghorn
Source:  ASNE, November, 1957
Doc ID:  1957006
Year of Publication:  1957
Abstract:  
Shot peening is a means of cold working the surface of metal parts by means of a hail or blast of round metal shot directed against the surface. It is equivalent to a myriad of small hammer blows impinged over the entire surface indenting the surface and causing plastic flow and work hardening of the surface metal. This work hardening of the surface metal increases its tensile strength and yield point and a small percentage of the beneficial results of shot peening are attributable to this effect. The greater benefit, by far, however, resutls from the fact that the surface metal is upset and put into compression; the surface compressive stress is extremely beneficial in obviating fatigue failures. What fatigue failures are and how shot peening helps to eliminate such failures will be dealt with later on.