Corrosion Phenomena of High Temperature Alloys by Helium Impurities in the Primary Coolant of HTGR

Abstract The primary coolant circuit of the high temperature gas-cooled reactor (HTGR) contains trace impurities. A nickel base alloy would corrode when exposed to an atmosphere at a and for long time. protective oxide scale formed by chromium is important factor prevent severe corrosion alloys. Corrosion tests were conducted on Inconel 617, Incoloy 800H, Hastelloy X, T-22, which are commonly used in steam generator HTGR. alloys helium with impurities 48 hours 950°C. results analyzed weighing, scanning electron microscopy (SEM) probe microanalyzer (EPMA). All four scales this atmosphere, but they differ capacity resist corrosion. Therefore, carbon transfer phenomenon observed experiment varies different In addition, Cr Inconel617, expected depletion near layer occurred, consistent from theoretical analysis.