Inconel 617의 고온열화에 따른 미세구조 및 고온 기계적 특성

Abstract

Inconel 617 is a candidate tube material for high temperature gas-cooled reactors(HTGR). The microstructure and mechanical properties of Inconel 617 were studied after exposure at high temperature(1050°C). The dominant oxide layer was Cr-oxide. The internal oxide and Cr-depleted region were observed below the Cr-oxide layer. The depth of Cr-depleted zone and internal oxide increased with exposure time. The major phases of carbides are M23C6 and M6C. The composition of M23C6 and M6C were determined to be Cr-rich and Mo-rich, respectively. M6C carbide is more stable than M23C6 at high temperature. From the results of high temperature compression test, there were no significant changes in hardness and yield strength upon increasing exposure time.