Crack Initiation And Growth In Shot-peened And Prestrained Peened High Strength Steel

Author:  Berns, H. and Weber, L.
Source:  Conf Proc: ICSP-2, (p. 84-89)
Doc ID:  1984010
Year of Publication:  1984
Abstract:  
A low alloy high strength CrMnV-steel at 0.5% carbon content was quenched and tempered to a tensile strength between 1200 and 1850 MPa. Flat examples of 100 x 15 x 400 mm were shot-peened without or with a prestrain of 0.75 the yield strength. These two surface conditions are compared in four-point bending tests to give a fatigue life between 10 exp 4 and 10 exp 6 cycles. Special consideration is given to crack initiation which is registered by on-line ultrasonic surface waves. By means of five detectors it is possible to locate individual cracks and follow their extension separately. These investigations are accompanied by a microstructural and fractographic analysis. Descriptors: High strength steels-- Mechanical properties; Chromium molybdenum vanadium steels-- Mechanical properties; Fatigue (materials); Cracking (fracturing)-- Stress effects; Residual stress; Shot peening