Microstructural analysis of shot and laser shock peened grey iron for increased fatigue strength

Author:  S. Slawik, P. Leibenguth, D. Rathmann, C. Gachot and F. Mücklich
Source:  Conf Proc 2014: ICSP-12 Goslar, Germany (pgs.232-237)
Doc ID:  2014081
Year of Publication:  2014
Abstract:  
Mechanical surface treatments such as shot or laser shock peening are used in technical applications to improve lifetime properties of components. This is mainly caused by the formation of a compressive residual stress state and microstructural defect density fields in near surface regions that lead to a retardation of crack initiation and propagation. In particular for grey iron that is still in use for industrial applications, the stress state is decisive to avoid crack initiation. In this study cast iron with flaky graphite has been surface treated by conventional shot peening and laser shock peening to improve lifetime properties. A first comparison of microstructure modifications due to the different peening techniques is done. As first results, the residual stress state by means of X-ray stress analysis and the deformation state by means of electron backscatter diffraction (EBSD) and backscatter detector imaging are presented.