Experimental study on the bending fatigue characteristics of shot peening gears

Abstract This paper investigates the influence of shot peening on the bending fatigue characteristics of 20MnCr5 carburized involute cylindrical spur gears, which are widely used in vehicle transmission systems. Surface integrity is analyzed for gears with and without the shot peening process to illustrate the effect of shot peening. A bending fatigue test is carried out for both two kinds of gears, and the differences in crack failure characteristics in the source area are analyzed using a scanning electron microscope (SEM). It is found that shot peening can greatly improve gear surface integrity, although it harms surface waviness. Shot peening can effectively increase gear bending strength and restrain the crack initiation from the gear surface.