INFLUENCE OF SHOT VELOCITY AND SHOT SIZE ON ALMEN INTENSITY AND RESIDUAL STRESS DEPTH DISTRIBUTIONS

摘要

More than 150 batches of shot peened specimens made of annealed or quenched and tempered steel 42CrMo4 were prepared and investigated. Shot size S110, S170 and S230 were used in combination with different mass flows, nozzle diameters and nozzle distances. A specific system for the direct measurement of the velocity distributions of the shots was employed and results were correlated with the Al-men intensities measured (Zinn, Schulz, Kopp, et al., 2002). In this paper, for characteristic examples the residual stress depth distributions produced and the full width at half maximum (FWHM) values of X-ray interference lines are discussed in dependency of Almen intensities and shot velocities. Maximum amounts of compressive residual stresses below the surface are only influenced by the materials state. All other peening parameters mainly influence the thickness of the layer with compressive residual stresses. In this context, shot diameter and shot velocity are most important.