Influence of Shot Peening and Deep Rolling on High Temperature Fatigue of the Ni-Superalloy Udimet 720 LI

Author:  Lindemann, Grossmann, Raczek and Wagner
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002059
Year of Publication:  2002
Abstract:  
Authors Janny Lindemann 1), Kim Grossmann 2), Thomas Raczek 1) and Lothar Wagner 1) Chair of Physical Metallurgy and Materials Technology, Technical University of Brandenburg at Cottbus, Cottbus, Germany 2) Rolls-Royce Deutschland, Dahlewitz, Germany Abstract The Ni-superalloy Udimet 720 LI is typically used for application as turbine disc material for gas turbines. The present investigation was undertaken to determine if the elevated temperature fatigue strength can be improved by mechanical surface treatments. Shot peening and deep rolling were performed on circumferentially notched (kt = 2.3 and 3.5) specimens. Axial fatigue tests were performed at T = 650 C using a stress ratio of R = 0.1. The fatigue performance will be compared with electrolytically polished references.