Oxidation Kinetic and Oxide Scale Morphology of Fe-33Ni-19Cr Ni-Based Superalloy

In the present study, outcome of various grain size of heat treated Fe-33Ni-19Cr Ni-based superalloy at high temperature cyclic oxidation condition was investigated. The Fe-33Ni-19Cr Ni-based superalloy was experienced a series of heat treatment process at two assorted temperatures, which are 1000 °C and 1100 °C, soaking for 3 hours and then rapid cooled by water quench. The heat treatment process produced a fine and coarse grain size structure. The cyclic oxidation test was performed for both heat treated samples at 700 °C under cyclic conditions in the laboratory air for 150 cycles. The weight change was measured discontinuously at different cycles to identify the kinetics of oxidation. SEM and FESEM outfitted with EDX spectrometer were utilized to analyzed the oxidation product. As a result, the weight change increased with time, with fine grain HT1000 sample recorded lower weight gain compared to coarse grain HT1100 sample. In addition, both sample formed uniform and continuous oxide scale on the alloy surface.