An analysis of the transition from metal erosion to oxide erosion

Abstract

The solid particle erosion of metals and alloys at elevated temperature encounters different mechanisms of interaction between erosion and oxidation, depending on the nature of the oxide scale. Two important mechanisms are metal erosion and oxide erosion. It has been postulated that the transition from metal erosion to oxide erosion is governed by the depth to which deformation extends beneath the oxide scale as compared to the thickness of the scale. In order to validate this postulate, erosion rates of NiO scale having two different thicknesses (100 μm and 20 μm) were determined as a function of impact velocity, impact angle and erodent size, and compared with that of the substrates obtained by machining the oxide scale. The results clearly establish that there is a slow transition from the metal erosion to oxide erosion as the ratio of the thickness of the oxide scale to the depth of deformation changes from 0.5 to 3.