Influence of grain size on the isothermal oxidation of Fe-33Ni-19Cr alloy

Abstract

This research focuses on the influence of grain size on isothermal oxidation of the alloy Fe-19Cr-33Ni. Alloy Fe-19Cr-33Ni have been cut to the desired size and have been grind using a variety of grit sandpaper and weighed using an analytical balance and also measured using a vernier calliper before oxidation test. Fe-33Ni-19Cr alloy has been through oxidation at a temperature of 850˚C for 150 hours. Characterization of oxidized sample was carried out by observation of the microstructure, oxidation kinetics, hardness testing, analysis phase, and followed by analysis of surface morphology. Based on this research, it was found that the weight changes increases with increases temperature and also the grain size. In addition, the analysis showed that all samples oxidized phase indicated the formation of oxide phases. Next, the surface morphology analysis showed the formation of a uniform oxide layer in a short period of exposure while in 150-hour exposure showed a thick oxide layer and the oxide layer which is also torn off due to too long exposure to high temperature oxidation