Cavitation erosion behavior of Inconel 690 alloy

The cavitation erosion behavior of Inconel 690 alloy was investigated using 20-kHz vibratory cavitation test equipment and analyzed by scanning electron microscopy (SEM). To clarify the development of cavitation damage with time, scanning electron photographs were recorded for various test durations, where the time was measured from the commencement of vibration. The results showed that the cavitation erosion damage in Inconel 690 alloy occurred initially at the grain boundary, twin boundary, and the interface between the precipitate and the matrix. Pitting also occurred along with cavitation. The causes of the weight loss in the incubation period were the small TiN precipitation run off and the loss of deformation area at not only the grain boundary but also the twin boundary. In the acceleration period, the weight loss originated from the combined effect of big craters that resulted in larger volumes of material loss.