Effect Of Shot Peening Variables On Bending Fatigue

Author:  Horvath, J. A.
Source:  Conf Proc: ICSP-1, (p.229-236)
Doc ID:  1981023
Year of Publication:  1981
Abstract:  
A fractional factorial experiment was run to determine the effects of shot peening variables of shot size, wheel speed (shot velocity), and shot flow rate on the magnitude and distribution of residual stress, and on fatigue life of SAE 1074 steel. Shot peening has a beneficial effect on fatigue life, increasing the B63.2 life by about a factor of five over unpeened samples tested in three point bending. Highest fatigue lives were obtained when peening gave a high residual surface compressive stress for a shallow depth. A total shot stream energy concept was developed as a characteristic parameter of the process and indicates that an optimum value of energy exists to obtain maximum fatigue life. Surface residual compressive stress reached a constant value at a relatively low shot stream energy while higher shot stream energy produced deeper and higher residual compressive stress levels. Descriptors: Shot peening; Fatigue life; Residual stress