Resistance Against Cavitation Erosion of 14 Chromium Steels

For 14 chromium steels of different composition and structure, cavitation-erosion damage has been studied and interpreted in terms of structure and strength properties. The use of chambered cylindrical specimens ensured a uniform attack from the very beginning of the erosion process and, thus, highly reproducible wear values. As could be expected on the basis of existing evidence, the duration of the incubation period is a function of the initial condition of the surface, as determined by the finishing process. The reciprocal rate of volume loss, occurring during the first steady-state period (which is characterized by a uniform attack of the surface, without formation of deep craters) (R_c), turned out to be a linear function of the “true” tensile strength, measured at maximum load. It does not depend on grain size, structure and elongation properties of the material. On the other hand, the tendency toward the formation of craters in the surface and the ratio R_c/R_∼, in which R_∼ is the reciprocal rate of volume loss, during the second, and final, steady-state period, are shown to be exclusively determined by structural parameters.