Effect of crystal orientation on the propagation of microstructurally short fatigue cracks

The propagation rates of microstructurally short cracks were measured in fatigued austenitic steel polycrystals. For transgranular crack propagation, the propagation lattice planes were determined using the electron backscattering diffraction method (EBSD) in the scanning electron microscope. There exists a remarkable difference of the propagation rates along {100} and {111} planes which can be explained by symmetric or non-symmetric action of slip systems in front of the growing crack.