Effect of Short-Time Annealing on Fatigue Strength of Shot Peened AISI 4140 in a Quenched and Tempered Material State

Author:  Menig, Schulze, Vohringer
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002043
Year of Publication:  2002
Abstract:  
Authors Rainer Menig, Volker Schulze and Otmar Vohringer, Institut fur Werkstoffkunde I, Universitat Karlsruhe (TH), Karlsruhe, Germany Abstract Increases of residual stress stability and alternating bending strength of shot peened AISI 4140 are obtained by subsequent annealing treatments. This is caused by static strain aging effects, which lead to pinning of dislocations by carbon atoms and finest carbides. It will be shown that by well directed annealing of a quenched and tempered AISI 4140 it is possible to maximize the positive effects of static strain aging without causing extended thermal residual stress relaxation. The amount of flow stress increases caused by static strain aging is quantified and correlated with the gain in alternating bending strength.