Per: Ana Paula Favero Fiorin (Universidade federal do espírito santo), Daniela Bahiense de Oliveira (UNIVERSIDADE FEDERAL DO ESPÍRITO SANTO), Antônio César Bozzi (UNIVERSIDADE FEDERAL DO ESPÍRITO SANTO)
Abstract:
When exposed to the action of fluids, equipments are subject to cavitation erosion wear. To mitigate this effect, superalloys and heat treatments such as solution treatment can be used. The Stellite 250 cobalt superalloy, was subjected to solution treatment and vibratory cavitation test, to investigate its behavior regarding wear by cavitation erosion. The as-cast specimens were solubilized at 1200 °C for 12 hours, with subsequent quenching in water. The characterization was performed using an optical microscope, stereoscope, microhardness and X-ray diffraction. The cavitation test was performed according to the ASTM G32 standard. The cavitation erosion resistance was analyzed by the accumulated mass loss as a function of the exposure time. The wear mechanisms were observed with the scanning electron microscope. After the solution treatment, the specimen showed mixed crystalline structure (FCC and HC), primary recrystallization and grain nucleation. The resistance to cavitation erosion of the solution treated specimen was lower than the as-cast specimen. The wear mechanisms observed for Stellite 250 alloy were sliding bands, formation of pits and craters.