Structural Aspects of Silt Erosion Resistant Materials Used in Hydraulic Machines Manufacturing

The corrosion effects caused by cavitation and silt erosion (abrasive erosion) phenomena lead to serious modifications in the structure of metallic materials from which are manufactured the important active components of hydraulic machines. In the first part of the paper, a brief presentation of the mechanism of silt erosion phenomenon comparatively with the cavitation one is made. The synergy between cavitation-erosion-corrosion is approached. The structure elements of the most used metallic materials corrosive resistant are described, too. It follows a comparative synthesis of specific structures stainless steels resistant to cavitation erosion and abrasive erosion. The structures of new stainless materials, originally obtained in the laboratory, are discussed on Schaeffler's diagram showing the influence of alloying elements on these forms of corrosion.