Shot Peening Effects on Residual Stress and Fatigue Behavior

Shot peening is a cold‐working surface treatment in which small spherical media are propelled at high velocity to plastically deform the near‐surface layer of a metallic component. This process induces a compressive residual stress field that counteracts the tensile stresses responsible for crack initiation and propagation under cyclic loading. Variations in peening parameters—such as intensity, coverage and shot material—govern the depth and magnitude of the compressive zone, the extent of strain hardening and the degree of surface roughness. Advanced strategies, including severe and gradient peening, promote nanocrystalline grain structures and optimised stress gradients, thereby enhancing fatigue resistance without incurring surface defects. Shot peening finds global application in aerospace, automotive and power‐generation industries, where extended component life and improved safety margins are paramount.

Research from Nature Portfolio

Recent studies have introduced gradient severe shot peening (GSSP), a novel treatment in which projection pressure is varied sequentially rather than held constant. By applying a controlled pressure ramp, GSSP creates a pre-hardening stage that improves the material’s tolerance to subsequent higher‐energy impacts. This approach yields deeper compressive residual stress profiles and lower surface roughness compared with standard constant‐pressure treatments. In steel specimens, GSSP has been shown to extend fatigue life by up to 30 %, largely through enhanced surface nanocrystallisation and the avoidance of over-peening defects. These findings underscore the value of pressure modulation in balancing surface hardening with microstructural integrity.

Shot Peening Effects on Residual Stress and Fatigue Behavior publication trend

The graph below shows the total number of articles in shot peening effects on residual stress and fatigue behavior across all publications each year (not limited to Nature Index journals).

Technical terms

Shot peening: A mechanical treatment in which spherical shots impact a surface to induce plastic deformation and compressive residual stresses. Residual stress: Locked‐in stress remaining in a component after external loads are removed; beneficial compressive residual stress impedes crack initiation. Fatigue life: The number of load cycles a material can sustain before initiation and growth of fatigue cracks lead to fracture. Almen intensity: A standard measure of peening energy, determined by the arc height of a calibrated steel strip subjected to peening. Surface coverage: The proportion of substrate area impacted by shots, expressed as a percentage, which influences the depth and uniformity of the induced stress field.

References

1. Investigating the effect of shot peening parameters on the peened surface damage using FEA. Results in Engineering (2023).
2. Effects of Conventional and Severe Shot Peening on Residual Stress and Fatigue Strength of Steel AISI 1060 and Residual Stress Relaxation Due to Fatigue Loading: Experimental and Numerical Simulation. Metals and Materials International (2020).
3. Introducing gradient severe shot peening as a novel mechanical surface treatment. Scientific Reports (2021).
4. Effects of Shot Peening and Cavitation Peening on Properties of Surface Layer of Metallic Materials—A Short Review. Materials (2022).
5. From conventional to severe shot peening to generate nanostructured surface layer: A numerical study. IOP Conference Series Materials Science and Engineering (2014).