Shot Peening Gives Parts Higher Fatigue Life

Author:  Nachman, Gerald
Source:  Diesel & Gas Turbine Progress, October, 1976
Doc ID:  1976007
Year of Publication:  1976
Abstract:  
One of the prerequisites of early fatigue failure of turbine blades, crankshafts, and connecting rods, leaf springs, piston rings and pins, to cite a few examples, is present from the moment these components are manufactured. This is residual surface tensile stress, unavoidably induced in most metal and alloy parts be machining, grinding and to an extent, by plating and other finishing and forming operations. Residual surface tensile stress creates microscopic surface fissures or "stress risers" between the metal grain boundaries. As the components undergo cyclic loading during operation of the equipment, the risers enlarge and propagate inword unitl premature fatigue failure resulst.