Application of image analysis for cavitation erosion resistance monitoring of some engineering materials

Abstract

Engineering materials are often used in various operating conditions including high temperatures, pressure, aggressive solutions, or cavitation erosion. The phenomenon of cavitation erosion is expected when fluid flow is present, which contains equipment such as turbine blades, high-speed propellers, or pump parts. Cavitation erosion usually causes surface degradation of material with defects that appear in the form of pits and fractures. Such loss of material leads not only to surface degradation but usually also to strength deterioration with the potential risk of failure and therefore also to shortening of material lifetime, thus requiring additional costs for failure analysis, repair, and replacement of parts. This paper will present the results regarding the resistance of various engineering materials to cavitation erosion. As materials, austenitic stainless steel 316L and CuAlNi shape memory alloy are selected and studied. The comparison of the behavior between these two materials in cavitation erosion conditions will be shown based on the results of mass loss and morphology analysis of the pits formed at the surface over time. Image analysis tools will be applied in order to quantify the surface damage level and to analyze selected morphology descriptors.