A series of tests on iron and steel in a water tunnel system, which simulated field conditions quite closely, showed that each material has its own process of erosion, and that in general the fracture of metals by cavitation turns from ductile to brittle with the lapse of testing time.
Fractures of iron and steel in the vibratory method turned, as in the water tunnel, from ductile to brittle. It was found also that the ductile-brittle transition is decisively influenced by experimental parameters such as temperature of the test liquid, frequency of the vibration, and corrosiveness of the test liquid.
Based on these experimental results, it was concluded that, in the vibratory test, the process of damage of a material can be changed to a great extent by choosing appropriate conditions of the test.