FATIGUE FAILURE OF SUS-304 CAUSED BY VIBRATORY CAVITATION EROSION

The mechanism of cavitation erosion is investigated in detail for SUS 304 stainless steel, a typical erosion-resistant material. Systematic observations of eroded surfaces and dislodged particles show that the predominant failure mode in cavitation erosion is fatigue. Characteris tic features of such failures include (1) packets of slip bands, (2) c racks that nucleate at regions of high stress (strain) concentration, (3) cracks that propagate first at an inclination to the surface and t hen parallel to the surface, and (4) fatigue striations and 'tire trac ks' on the rupture surfaces. These last two features are the most indi cative of a fatigue process. It is also deduced that massive voids acc ompanying pressure shock-rings are the most erosive kind of cavitation .