Correlation of Cavitation Damage Tests with Residual Stress Measurements

Using specimens of SS41 carbon steel, authors made a test on erosion by means of resonant frequency of 22 kc/sec, and simultaneously took accurate measurements of half-value breadth both in the surface and in its innerface through Cobalt Kα radiation and of residual stress. Authors' conclusion is as follows. Both in an erosive surface and in its innerface, residual stress is attributed to compressive stress, after maximum residual stress has taken place in the surface, the weight loss of specimen remarkably increases; consequently there can be recognized a certain time rate in this test duration. The internal residual stress before starting of the weight loss of the test piece being compared with the one after starting, there occurs some change from maximum to minimum nearly at the same depth. The comparative test on half-value breadth at different amplitudes results in that in each period of operation the testing amplitudes relate not to the pressure in the collapse of each one of the bubbles but to the number of bubbles in the collapse.