Residual Stress And Hardness Distributions Induced By Shot Peening

Author:  Tosha, K. and Iida, K.
Source:  Conf Proc: ICSP-4, (p.379-388)
Doc ID:  1990059
Year of Publication:  1990
Abstract:  
Hardness number is a resistance stress for micro-plastic deformation. It may be affected by the residual stress or distributed stress. This paper describes the relation between the hardness and the stress in the affected layer produced by shot peening. The material of the specimen is carbon steel (0.45%C) and the elastic stress field was induced by bending and tension of the specimen, and residual stress was induced by shot peening. The hardness was measured by micro-vickers hardness tester and the stress was measured by X-ray diffraction. Shot peening was performed under the following conditions; diameter of shot D mm: 2.2, velocity of shot V m/s: 35, Peening time : full coverage time. The results are as follows; (1) Hardness increases in compressive stress and decrease in tensile stress. (2) The maximum change in hardness number is -20 (HV) and the ratio of decrease is -9.8 %, wherein tensile stress increment is 460 MFa. (3) The influence on the hardness of the residual compressive stress induced by shot peening is the same to the elastic compressive stress of bending. (4) The residual stress distribution and hardness distribution produced by shot peening are changed by the thickness of specimen under the same shot peening condition. Descriptors: Shot peening; Stress field hardness; Hardness distribution; Residual stress; Size effect; Affected layer