PARAMETRIC STUDY OF RESIDUAL-STRESS DUE TO SHOT PEENING

Shot peening was carried out on an 6061-T652 aluminium alloy, the effects of two main peening parameters, the air blast pressure and the exposure time, on the depth of yield and the maximum residual stress induced in the shot peened specimens, being measured. For the residual stress, the traditional strain-gauge hole-drilling method and a laser holographic interferometry technique were used. Analysis of the experimental data showed that the residual stress is affected by the air-blast pressure to a power law, and that there is an exponential relationship between the maximum induced stress and the exposure time, an empirical equation for the relationship of the maximum stress with the pressure and time being thus obtained. A similar expression was arrived at also for the variation of the depth of the yield zone with pressure and time.