Shot Peening Versus Laser Shock Processing

Author:  Banas, G. and Lawrence,Jr., F.V.
Source:  Conf Proc: ICSP-4, (p. 95-104)
Doc ID:  1990071
Year of Publication:  1990
Abstract:  
Shot peening and laser shock processing effect on residual stress, hardness, and fatigue behaviour of welded 18 Ni(250) maraging steel is presented in this paper. Initiation-propagation model was used for fatigue strength predictions of as-welded, shot-peened, and laser-shock-treated specimens. Elastic stress concentration factor (K[t]) was determined using finite element analysis considering both tensile and bending stresses. Laser shock processing as well as shot peening altered both hardness and residual stress state of welded specimens; there was an increase in both hardness and compressive residual stresses. Fatigue strength was also higher, however, laser shock processing gave better performance in longer lives (>10[5] cycles), while in shorter lives (<10[5] cycles) no significant difference was found between shot peening and laser shock processing. The comparison of predicted and experimental results showed an agreement within 10-20%. Descriptors: Weldments; Shot peening; Laser shock precessing; Metallic fatigue; Residual stresses; Hardness