Surface modifications induced by shot peening and their effect on the plane bending fatigue strength of a Cr–Mo steel produced by powder metallurgy

The effect of shot peening on the plane bending fatigue strength of a 7.1g/cm3 sintered Cr-Mo steel was investigated. Shot peening provides surface densification, strain hardening, compressive residual stresses up to -700MPa, without impairing the dimensional and geometrical precision of specimens. Plane bending fatigue strength increases of 30%, irrespective to the different residual stress profiles obtained by changing the shot peening parameters. The improvement is mainly due to the surface densification and strain hardening. © 2010 Elsevier B.V.