Effect of shot peening on the surface integrity and fatigue property of gear steel 16Cr3NiWMoVNbE at room temperature

The gear steel 16Cr3NiWMoVNbE was shot peened using a range of pellet sizes and shot peening intensities. The surface morphology, residual stress field, and cross-section microstructure were examined, and the influence of surface integrity difference on the room-temperature rotary bending fatigue performance was analyzed. The results indicate that surface roughness, the depth of maximum residual stress, and dislocation density increase as shot peening strength and projectile size increase, whereas the value of surface residual stress decreases as shot peening strength increases. By shot peening, the rotary bending fatigue life of gear steel at room temperature was enhanced by 5.03 similar to 17.20 times. As the shot peening strength increased from 0.10mmA to 0.15mmA when AZB150 shot peening was utilised, the estimated median fatigue life of shot peening increased by 80.46%. When the shot peening strength is 0.10mmA, the estimated median fatigue life of shot peening increases by 2.02 times as the shot size increases from 0.15 mm to 0.30 mm. The actual maximum stress value taking the surface stress concentration coefficient into account was used to estimate the location of the hazardous components, which was confirmed by the fatigue source location study.