effect of environment on oxidation behavior and mechanical properties of inconel 617

Abstract

Inconel 617 is considered as tube material for high temperature gas-cooled reactors(HTGR). In the present study, the microstructure and mechanical properties of Inconel 617 were studied after exposure at high temperature (1050℃) in air and He environment. Oxide layers were analyzed by SEM and EDS. The dominant oxide layer was Cr-oxide. The internal oxide and Cr-depleted region were observed below the Cr-oxide layer. In the air environment, internal oxide layer and Cr-depleted zone are thicker than He environment because of higher oxygen partial pressure. The precipitated phases were identified in this solid-solution hardened alloy. The major phases are M23C6 and M6C types of carbides. The composition of M23C6 and M6C were determined by EDS to be Cr-rich and Mo-rich carbide, respectively.