Influence of Optimized Warm Peening on Residual Stress Stability and Fatigue Strength of AISI 4140 in Different Material Stat

Author:  Menig, Schulze, Vohringer
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002041
Year of Publication:  2002
Abstract:  
Authors Rainer Menig, Volker Schulze, Otmar Vohringer, Institut fur Werkstoffkunde I, University of Karlsruhe (TH), Karlsruhe, Germany Abstract Using a modified air blasting machine warm peening at 20 C < T < 410 C was feasible. An optimized peening temperature of about 310 C was identified for a 450 C quenched and tempered steel AISI 4140. Warm peening was also investigated for a normalized, a 650 C quenched and tempered, and a martensitically hardened material state. The quasi static surface compressive yield strengths as well as the cyclic surface yield strengths were determined from residual stress relaxation tests conducted at different stress amplitudes and numbers of loading cycles. Dynamic and static strain aging effects acting during and after warm peening clearly increased the residual stress stability and the alternating bending strength for all material states.