Effects of Cathodic Protection of Cavitation Erosion in Vibratory Tests

In order to clarify the effects of cathodic protection on cavitation erosion, cavitation erosion tests are carried out using a vibratory erosion apparatus, and the cavitation aspects are photographed with a xenon flash lamp of 1μs exposure time. With increasing cathodic current, cavitation noises and mass losses (ML) of cavitation erosion markedly decrease when the number of tiny hydrogen bubbles on the specimen surface as well as in the test water increases, and the mass loss rate (MLR) is related to the square of sound pressure level (SPL2) of cavitation ultrasonic noise. The decreases in SPL and ML are due to marked absorption of cavitation energy by hydrogen bubbles produced on the specimen surface.