The Influence Of Broken Shots On Peening Effect Of Hard Shot Peening

Author:  Watanabe, Hasegawa, Namiki, Natano
Source:  Conf Proc: ICSP-4, (p. 63-72)
Doc ID:  1990088
Year of Publication:  1990
Abstract:  
Hard shot peening characterized by its larger shot injecting energy with arc height higher than 0.7 mmA is becoming popular as one of the methods to enhance the fatigue durability especially for case hardened components. During this process many shots are broken compared to conventional peening process. In this study, to clarify the influence of broken shots on fatigue properties, two types shots having two different hardness respectively are prepared. Ervine tests reveals that one of them has many broken particles and another has a little. Using these two types shots specimens were hardly peened and fatigue tests are carried out to obtain S-N curve and Weibull charts. The specimens peened with shots containing many broken shots show wider distribution of fatigue life than the ones peened with shots containing of a little. It is concluded that broken shots degrade the stability of peening effect in hard shot peening. Descriptors: Hard shot peening; Carburized steel; Residual stress; Retained austenite; Fatigue test; S-N curve; Weibull chart