Influence of the Pre-Stressing on the Residual Stresses Induced by Deep Rolling

Abstract

Abstract. Deep rolling is a mechanical surface treatment, which main aim is to increase the fatigue life of components by reducing their roughness, increasing the surface hardening and inducing compressive residual stresses. The increase of certain process input parameters such as the applied pressure or the number of overturns leads directly to the raising of the induced compressive residual stresses. Nevertheless, a saturation point is always achieved, where the further increase of the parameters' levels does not change the induced residual stresses. For other mechanical surface treatments, like shot peening, several pre-stress techniques were employed in order to further increase the induced residual stresses without raising the shot intensity or the coverage percentage. Pre-stressed shot peening with the means of bending or torsion is an established processing. Up to now, a few investigations are available regarding the pre-stressing techniques applied to deep rolling. Therefore, this paper offers a newly designed finite element model, built to calculate the induced residual stresses by bending, consequent deep rolling and springback. A four point bending setup with different pre-stress levels was employed and the influence of pre-stress levels on the induced residual stresses was investigated. Additionally, the applied deep rolling pressure was also varied in order to optimize this hybrid processing. At the end, the anisotropy of the induced longitudinal and transverse residual stresses due to the bending and deep rolling was analyzed.

Deep Rolling Techniques: A Comprehensive Review of Process Parameters and Impacts on the Material Properties of Commercial Steels

“…Lately, numerous innovative and novel deep rolling techniques like pre-stress deep rolling [90,91]; diffusion with deep rolling [92,93]; turn-assisted deep rolling [94]; hard turning and deep rolling [95,96]; in-process semisolid deep rolling [97,98]; intermediate deep rolling in additive manufacturing [99,100]; and centrifugal force-assisted deep rolling [101] were reported. The major objective was to enhance the effect of conventional DR and/or reduce the processing time while ensuring similar benefits.…”