THE MICROHARDNESS EVOLUTION IN THE CAVITATION DAMAGE

Abstract

The cavitation damages of the cylinder liners and of the cylinder blocks of the Diesel engines, on the surfaces cooled by water, was determined, in principle, by the cylinder liner vibration. In this way, we can affirm that the cavitation resistance of the cylinder liners is dependent the vibration characteristics of cylinder liners and on the mechanical characteristics of the material alloys. This paper presents the microhardness variation of superficial layer with time testing and for some thickness of the cylinder liner. They are observed, after 100 hours time testing on stand, that the maximum reduction of microhardness values it is produced in the action plan of the excitation force, and especially for the small thickness of the cylinder liner. This problem, associated with the specialty literature data, lead to significant reduction of the cavitation resistance in the mentioned zones (the weight losses by cavitation wear increase by microhardness reduction of the cast iron).