Dent And Affected Layer Produced By Shot Peening

Author:  Iida, K.
Source:  Conf Proc: ICSP-2, (p.283-292)
Doc ID:  1984012
Year of Publication:  1984
Abstract:  
Some characteristics of shot peening are presented. Shot peening consists of making a dent by using the impact of a steel ball. Laws of dent formation relating to the diameter, depth and volume for the outside of the dent and the inside of the dent, which is the yield zone of steel, are obtained from the function of velocity and dia. of the steel ball and hardness of the material to be peened. The yield zone produced by shot peening makes an affected layer which involves residual stress, change of hardness, and so on. The hardness distribution in the affected layer shows work hardening and work softening, and the distinction between these cases is clarified. The work softening phenomenon occurs in cold working of prestrained metals under certain combined strains. The work softening phenomena generally occurs in prestrained metals, but not in normalized or annealed metals. In the case of shot peening, work softening or work non-hardening in the peened surface appears in rolled or compressed metal, especially under high intensity peening conditions for highly prestrained material. This phenomenon differs from the Bauschinger effect and appears in such metals as steel, brass, Cu and A1. Descriptors: Shot peening; Plastic deformation; Residual stress; Surface hardness; Strain hardening; Strain softening; Prestraining