Cavitation Damage of Stainless Steel, Nickel, and an Aluminum Alloy in Water for ASTM Round Robin Tests

The results of NASA cavitation damage studies for an ASTM round robin cavitation test program are described. AISI type 316-stainless steel, nickel 270, and 6061-T6 aluminum were tested for resistance to cavitation damage in water at 75 deg F (23. 9 deg C) under 1 atmosphere pressure. A magnetostrictive transducer was used to vibrate the specimens at a frequency of approximately 25 000 hertz with a total displacement amplitude of 0.00175 inch (4. 45 x 10(exp -2) mm). The stainless steel was the least damaged and the aluminum alloy showed the heaviest damage. On the basis of volume loss and mean depth of penetration after 160 minutes of test, aluminum sustained damage approximately 45 times greater than stainless steel. Metallographic examination of damaged specimens showed that undercutting and random surface attack occurred with all three materials. Some subsurface deformation was indicated by slip lines in the 316 stainless steel specimen.