Effects of Severe Deformations and Martensitic Phase Transformations to Fatigue Life Assessment of Austenitic Steels

摘要

The life limited parts (LLP) determine the service life of an aero engine.All LLP's are surface-treated, e.g.shot peening, laser peening, deep rolling etc., to improve material performance under extreme loading conditions.The surface treatment induces material distortions and high roughness into the subsurface, besides the residual stresses.Especially, in some steels the martensitic phase will be formed due to severe deformations.Material micro-structures have been changed substantially.Evolution of the surface treated component needs detailed information and understanding of all these micro-structural changes to the surface treatment.