Fundamental Studies of Cavitation Erosion : In the Case of Low Cavitation Intensity

Abstract

Previously, the authors reported on the severe erosion where the pit was made by a single blow of cavitation pressure. The present paper deals with the erosion of mild steel under cavitation of comparatively low intensity. Under the test conditions, the incubation period is found in early stage of damage progress, where slips and plastic deformations occur in ferritic crystals but not in pearlitic crystals. From these, the blow intensity of the cavitation is known to be tens of thousands of atm. Cracks are made by the accumulation of plastic deformations and they propagate to a falling off of large particles. Neither residual stresses nor cold worked layers are found in the damaged portions under this progressing stage. This may be one of the characters of erosion under low cavitation intensities.