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The intergranular corrosion (IGC) resistance of Inconel 625 produced by laser powder bed fusion was investigated according to ASTM-G28 method A. Unexpected severe corrosion near fusion boundaries was found. The initiation and expansion of corrosion along fusion boundaries and the relationship between microstructure and corrosion behavior were analyzed. This unusual corrosion behavior was related to the Volta potential variation near fusion boundaries. This Volta potential difference was caused by the Al 2 O 3 nanoparticles and Mo, Nb-rich precipitates near the fusion boundaries. This finding may enhance the understanding of corrosion behavior of LPBFed nickel alloys. ● LPBFed IN625 exhibits unexpectedly high corrosion susceptibility near fusion boundaries duringASTM-G28 method A test. ● Corrosion rate of LPBFed IN625 was tripled compared to wrought IN625 due to severe corrosion near fusion boundaries. ● TEM observation of specimen found concentration of Al 2 O 3 nanoparticles and Mo,Nb-rich precipitate along fusion boundaries. ● Galvanic corrosion and the localized corrosion are responsible for the corrosion susceptibility. [ABSTRACT FROM AUTHOR]