CAVITATION EROSION OF IRON AND STEEL

A study has been made of the mechanisms and rates of cavitation erosion of iron and plain carbon steels. The high strain rate produced by cavitation results in the development of high densities of deformation twins in iron and the subsequent erosion of the metal by cleavage fracture. Erosion of the ferrite phase also dominates the failure of the normalized and spheroidized steels and, consequently, their erosion resistance is negligibly greater than that of the iron. Only the martensitic structure exhibits a significantly improved resistance. These results imply that a coarse (1 to 2 μm) second phase is not sufficient to provide protection against cavitation and that a change in the strength of the weakest phase-in this case, the ferrite-is required for an increased incubation period and decreased erosion rate. © 1978 American Society for Metals and The Metallurgical Society of AIME.