Multiaxial high cycle fatigue of 304L stainless steel with a small defect

The influence of a small defect on the multiaxial fatigue strength of 304L stainless steel was experimentally investigated. The fatigue tests were carried out on specimens containing a cylindrical defect with area = 400 µm. Five fully reversed loading paths were employed: tension-compression, torsion, in-phase, 90° out-of-phase, and square shape. Crack orientation in the vicinity of the defect was examined at and just above 2 × 106 cycles (run-out condition). The fatigue limits and crack angles measured were used to evaluate a tensile-based critical plane criterion for small defects. Predicted and measured results were in good agreement, indicating a tensile-dominated failure mechanism in the range of experimental conditions studied.