Peening Effect on Machining of Steel

Author:  K.Iida, J.Ito Meiji University
Source:  The Shot Peener magazine, Vol 09/Issue 4, Winter 1995
Doc ID:  1995047
Year of Publication:  1995
Abstract:  
Reprinted from ICSP4 Abstract Generally, machinery consist of various machined parts. One of the element of the reliability for machinery is endurance limit related to fatigue strength. Fatigue test was performed on various specimens machined with several nose radius tips under the same machining condition and on shot peened specimens with small glass beads after machining. Experimental conditions are as follows: machined metal is medium carbon steel (0.45%C), tip of cutting tool is cermet (NX33-Mitsubishi), nose radius was varied from 0.2 - 1.6 mm, machined surface roughness was 6 - 24 um Rmax, glass beads diameter is 0.18 - 0.21 mm, blasting pressure and time is 0.59 MPa and full coverage time respectively, fatigue test was performed with rotary bending machine, residual stress was measured by sin2u method of Xray diffraction on peripheral and axial direction. Nose radius of cutting tool affects remarkably surface roughness and residual stress. On one hand fatigue strength was not affected surface roughness but depends upon the surface residual stress of machined or shot peened after machining. Peening effect with small glass beads was excellent on fatigue strength for machined specimens. Keywords: Reliability of machine, machining, cermet, surface roughness, fatigue strength, residual stress, peening effect, glass beads, Xray diffraction.