Experimental Investigation On Residual Stress Of High-Strength Steel After Shot-Peening And Its Simulation

The effect of different shot-peening regimes on residual stress fields of the high strength steel was investigated and simulated by using a finite element method.By employing the X3000 X-ray diffraction stress analyzer and the electrochemical polishing method, the residual stress of the high strength steel along the shot-peened layer was determined layer by layer. Buy using X-ray diffraction analyzer, the crystal structure of specimen after shot-peening was analyzed. Meanwhile, the micro-hardness distribution along the shot-peened layer was determined, and the microstructure of the high strength steel was also observed. A model was proposed by using a finite element method and it was simulated by employing different velocities, rigidities and diameters of shots. The experimental results indicate that, with increasing of the shot-peening time, both depths of maximal compressive residual stress and shot-peened layer are increased, while, the value of surface compressive residual stress is decreased. The depth of shot-peened layer is strongly affected by the diameters of shot and the value of residual stress is improved when the diameter of shot is increased. With the increasing of the shot-peening intensity, the maximal compressive residual stress and depth of shot-peened layer are improved. The surface compressive residual stress is increased after secondary shot-peening by using glass or ceramic shot.After shot-peening, both the number of dislocation and micro-hardness increase.The finite element model of shot-peening was established by the software ANSYS. In this model, a few important parameters were considered and different results of residual stress fields were obtained. The simulated results are agreed to the experimental one therefore, this model is effective and can be employed to predict the residual stress fields of shot-peened specimens.