Effect of Shot Peening on Fatigue Strength of Phosphor Bronze C5191

Author:  Katsuji Tosha, Yoshinori Ueno, Kisuke Iida
Source:  Conf Proc: ICSP-7 (pg 344-349)
Doc ID:  1999047
Year of Publication:  1999
Abstract:  
This paper deals with the effect of shot peening on the fatigue strength of phosphor bronze, which is widely used for springs of the electric appliances. Shot peening is performed for phosphor bronze with glass and steel shots by air blasting machine. The effects of residual stress, hardness and surface roughness are discussed, and the following results are obtained; (1) This bronze is the suitable material for shot peening owing to its characteristics such as the high work-hardenability. (2) The peening effect by steel shot is larger than by glass shot, and the more the shot size, the more the peening effect. (3) The influence of the surface roughness on the fatigue strength of this bronze is larger than the hardness and the residual stress. (4) The reduce of the cross sectional area of phosphor bronze is possible up to 40% by shot peening in use as spring. (5) The maximum increasing ratio of fatigue strength is 131% compared with the unpeened bronze under peening conditions such as a0.3 mm steel shot, 0.2 MPa air pressure and 600% area coverage.