Evaluation of the residual stresses induced by shot peening on some sintered steels

Abstract

The effect of shot peening treatment on sintered steels plates were analyzed in terms of micro-structural and mechanical properties and residual stress profiles. Two high performances powder metallurgy steels were considered: the former was obtained starting from diffusion bonded powders, whereas the latter starting from pre-alloyed powders. Two different nominal densities were considered, 6.9g/cm3 and 7.1g/cm3. After a preliminary optimization, two shoot peening cycles were selected and carried out on the investigated materials. Residual stresses after the treatment were measured by means of the hole drilling technique and related to the mechanical properties and the surface densification of both steels, varying the nominal density.