The long-term corrosion behavior of IN-RAFM steel in molten Pb-Li upto 10, 000 h of exposure was studied in a rotating disc corrosion test facility at 823 K. As-received IN-RAFMS material possessed an air-formed surface layer containing oxides of Fe, Ce and W. Precipitation of chromium carbides at the grain/lath boundaries of as-received IN-RAFMS led to grain boundary attack by liquid Pb-Li during the initial “Incubation Period” which depicted slow dissolution of surface oxides and lesser corrosion rate. Complete dissolution of oxide layer altered the corrosion mechanism from grain boundary attack to matrix dissolution thereby increasing the corrosion rate. © 2021 Elsevier Ltd