Fundamental Studies on Cavitation Erosion : Observation of the Eroded Surface by SEM under Corrosive Liquid

To clarify the effects of corrosive liquid on the behavior of cavitation erosion, erosion damage of carbon steel in salt water has been compared with that in ion-exchanged water in a microscopic view by means of observation of the eroded surface by an SEM, and the following results are obtained. The erosion damage is highly affected by the grain orientation on the test surfaces. That is, on easily corroded grains many corrosion pits are formed originating from the crack propagation. However, on not easily corroded grains, slip bands are dissolved as soon as they are created, and therefore cracks are hardly formed in salt water unlike in ion-exchanged water.