The RAFM (Reduced Activation Ferritic/Martensitic) steel is considered as one of the promising candidatestructural materials for LFRs (Lead alloy-cooled Fast Reactors) and ADS (Accelerator Driven Sub-critical system),and its compatibility with liquid metal and radiation-resistant properties have been extensively studied because ofthe requirements of reliability and safety of the blanket[1]. A number of corrosion experiments of RAFMs (Eurofer97, T91 and 316L, etc.) in liquid LiPb alloy have been investigated, and the corrosion results show that these Febasedsteels suffered more serious corrosion attack from 480 to 550 ?C, and the corrosion layer is made of the oxidelayer (Fe3O4 and CrxFe3?xO4) at steels' surface. Generally speaking, during the stage degeneration of material, theformation of corrosion layer is one of the important features of the process[2]. Cracking, blistering, embrittlementand other changes in materials may be induced by corrosion layers, and the corrosion layers have independentcompositions, structures and radiation-resistant properties with distinguished from the alloy matrix. In a word, inorder to further clarify the applicability of Fe-based structural materials in nuclear facilities, we should study notonly the RAFM steel itself but also its corrosion layer (Fe3O4, mainly). So we report on modifications of mechanicalproperties of Fe3O4 corrosion layer irradiated with high-energy ion.