Microstructure Deformation of Austenitic Superalloy Steel after Arc Plasma Sintering

Microstructure deformation of 56Fe16.6Cr25Ni0.9Si0.5Mn austenitic superalloy (AS) has been investigated in this study. The superalloy was produced from a mixture of granular ferro-scrap, ferrochrome, ferrosilicon and ferromanganese raw materials by casting method and then annealed using arc plasma for 4 and 8 minutes. The superalloy has been proposed in nuclear as well as fossil power plant facilities such as vessels and heat exchangers. A combination of microscopy investigations by means of the Optical Microscope (OM), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques was carried out in order to get detail information about the microstructures especially fine structure and its deformation of superalloy steel. It can be resumed that the austenitic superalloy microstruture is composed by dendrites of -austenite, separted by eutectic structure of Fe-Cr-C alloy. APS for 4 to 8 minutes leads to form microstrain, , from 4.60x10-3 to 5.39-4.06x10-4.