14th International Conference on Shot Peening

Experimental Assessment of the Effects of modified Stress Peening Treatments on Surface Layer States and Fatigue Behavior in Leaf Spring Steel 52CrV4Mo

A. Klumpp, C. Grau, R. Rößler, D. Dapprich, S. Dietrich, V. Schulze

Institute for Applied Materials (IAM-WK), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany, Stresstech GmbH, Rennerod, Germany

University of Malta, Department of Metallurgy and Materials Engineering, Faculty of Engineering, Msida MSD 2080, Malta – ann.zammit@um.edu.mt (Corresponding author)

Abstract

This paper was derived within the EU-project “LEAFSLIM” and deals with surface states and fatigue behavior of quenched and tempered leaf spring steel 52CrV4Mo after conventional and modified stress peening treatments. An experimental setup for warm peening of specimens pre-stressed in bending was developed. A combination of inductive and continuous flow air stream heating was used in conjunction with a hydraulic load device to achieve reproducible surface layer states. Residual stresses and penetration depths in prestress direction reached a maximum (by amount) of approximately -1200 MPa and 0.6 mm, respectively. Warm and double peening did not significantly affect the fatigue behavior in the HCF range. Instead, a dominant influence of surface roughness on fatigue lives was found.