Effect of Shot Peening on Fatigue Strength of Notched Specimens

Author:  Shengping, Chengjie, Mei, Renzhi, Xiangbin
Source:  Conf Proc: ICSP-5, (p.150-153)
Doc ID:  1993068
Year of Publication:  1993
Abstract:  
Bending fatigue tests were carried out on smooth and notched (stress concentration coefficient Kt=1.5 and 3.0) specimens of 40Cr steel to determine the fatigue strength for 5X10 6 by up and down method. The specimens were shot peened and ground after heat treatment (quenched and tempered at 200C and 550C). Special attentions were paid to determined the positions of crack sources to subsurface and results in higher improvement in fatigue strength. The apparent fatigue strength of notched specimens tempered at 550C even reaches that of the crack source after shot peening still initiates at the root of the notch from the surface and the improvement of fatigue strength is not so significant as in above case.