STUDY OF M23C6 PRECIPITATION IN A 45Ni-35Cr-Nb ALLOY

Abstract

The 45Ni-35Cr-Nb alloy, commonly known as ET45 micro, produced in the form of centrifugally cast tubes, was studied by means of optical microscopy after aging treatments at 1073 and 1173 K for different times. A description of M23C6 secondary carbides precipitation phenomenon was made as a function of time. The analysis after using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) model showed that the secondary carbide precipitation occurs in a single stage. It was found that this phenomenon, which is assisted by diffusion, has an activation energy of 196 kJ/mol.