Abstract
In order to find alternative solutions for protection of hydraulic turbine components against cavitation, a fluid elastomer layer, curing at room temperature, was deposited onto a martensitic stainless steel substrate. The resistance of the coating to cavitation erosion was determined by the vibratory indirect method, using ultrasonic equipment with piezoelectric converter and the microstructure of the polymer was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The authors compared the cavitation erosion resistance of the elastomer layer with that of the base material (martensitic stainless steel) as well as that of protective cold hardening austenitic stainless steel coatings, deposited by overlay welding onto the base material. The experimental results revealed that the elastomer coating ensures better resistance to cavitation erosion than both stainless steel types.
Keywords: cavitation; cavitation erosion resistance; elastomer; stainless steels; hydraulic turbines