Analysis of Cavitation Erosion Resistance of Grey Cast Iron EN-GJL-200 by the Surface Induction Hardening

摘要

By surface hardening of the cast iron having metallic matrix consisting of pearlite and fine lamellar graphite separations, it has been aimed an increase in hardness and wear resistance. Testing of cavitation erosion resistance was done in the laboratory in accordance with the standard ASTM G32 2010. The mass losses curves, depending on the duration of the cavitational attack by induction hardened and tempered at 220 °C samples, were analysed in comparison with those samples obtained after the stress relief annealing at 525 °C. The hardness measurements performed on the longitudinal section of the cavitation samples beside the microstructural investigations of the eroded surfaces allowed the explanation of the wear mechanism both by the action of the graphite stress concentrator and also by the sensitivity of the metallfc mass to the notch effect.