Volume 11, Issue 2 (March 1983)
Vibratory Cavitation Tests at 200-kPa (2-Bar) Suppression Pressure
Cavitation erosion of 1100-0 and 2024-T-4 aluminum, 1018 carbon steel, 316 stainless steel, and 3% carbon cast iron was measured in tap water by vibratory horn at 200-kPa (2-bar) suppression pressure, at various temperatures and amplitudes. Erosion rate (MDPR) and incubation period (IP) were computed according both to total specimen area and to actual area eroded. Maximum damage depth penetration rate DmPR was also measured. Actual eroded area and maximum damage depth penetration rate are also presented. These are of substantial practical interest, since maximum damage depth Dm is often the best criterion to indicate failure. Incubation period IP is also considered to have more precise meaning if calculated according to actual eroded area. Temperature effects upon MDPR are reported. According to the test data at 200-kPa (2-bar) psv (where psv = p − pv, where p = static pressure and pv = vapor pressure) as well as the previous data at 100-kPa (1-bar) psv and some pertinent literature, MDPRmax occurs in the range 60 to 70°C (140 to 160°F). A new nondimensional damage depth parameter C = Dm/MDP, where MDP is the mean depth of penetration, has been defined. C versus horn amplitude is found to be an approximately exponential function for the ferrous alloys, but insufficient data is yet available to define similar trends for the aluminums. Scanning electron microscope photomicrographs of eroded surfaces of five materials tested show the pitted honeycombed surfaces, somewhat different for the different materials.