Investigation of the Surface Residual Stresses in Single and Multiple Trace Deep Rolling on Flat AISI 4140 Specimens

Author:  Nataliya Lyubenova, Dirk Bähre
Source:  ICSP-13
Doc ID:  2017108
Year of Publication:  2017
Abstract:  
Abstract: Mechanical surface treatments like deep rolling (DR) can be implemented in the components’process chain in order to increase their fatigue strength. Even the benefits of the application of DR are well known, its implementation is nowadays still supported with extensive experimental work. Many attempts were made to simulate the DR process with the finite element modelling (FEM) in order to reduce the experimental costs. Nevertheless, the complexity of the process hinders the establishment of the FEM as a standard implementation tool. This paper describes another endeavor to simulate the DR process which contrary to most available finite element (FE) models was applied on a flat instead of on an axis-symmetric geometry. Furthermore, the model represents a DR as a single trace instead of an area treatment. For this task the Explicit module of the FE code ABAQUS was employed and the investigation focused on the residual stress surface distribution. Different process parameters were varied in order to observe their influence on the calculated residual stresses. Additionally, X-ray diffraction (XRD) measurements were compared to the FE results for the sake of the FE model verification. In some cases, the measurements and the calculations in the area of the DR trace were in acceptable agreement. However, there were some deviations between predictions and actual measurements. To minimize the deviations, the FE model must be further optimized, as well as the accuracy of the XRD measurements improved. Also, the FEM showed that the residual stresses induced by DR widely exceed the width of the DR trace itself. Therefore, additional experimental work must be carried out to fully validate the FE model.