Vibratory cavitation erosion in aqueous solutions

Vibratory cavitation erosion tests on AISI-SAE 1018 carbon steel in tap water and in mild (0.1 M) aqueous solutions of CaCO₃, CaO, NaHCO₃ and NaOH were conducted at a temperature of 80 °F (27 °C), a double amplitude of 1.38 × 10^?3 in (35.1 μm) and a pressure of 1 atm. For the maximum (150 min) test duration the weight loss in tap water (no additive) is the smallest. However, this is not the case for shorter test times. The biggest difference between weight losses among the various solutions is about 10% – 30%, which is somewhat beyond natural data scatter for such vibratory tests. Released gases and also particles may play an important role in the results.There are three easily distinguishable damage regions for all cavitated surfaces, i.e. generally undamaged rim, central heavily damaged region and transition region, as for most vibratory tests. The relative areas of the three regions are about 53.5%, 0.13% and 46.4% respectively for the present tests.The erosion rate and extent of the damaged regions do not depend substantially on the solute tested. The very small area of the heavily damaged central region is presumably due to the relatively low horn amplitude used in these tests. The increase in damage rate with respect to tap water is about 50% for the maximum test duration.Surface photographs and scanning electron microscopy photomicrographs (for a test duration of 150 min) are presented. Cracks, intercrystalline fractures and single-blow craters are most concentrated in the central region, as would be expected.