Lead-cooled fast reactors (LFRs) characterized by their high safety, high economic efficiency, and the ability to transmute radioactive nuclides, represent one of the most promising Generation IV reactor designs for practical implementation. Liquid lead-bismuth eutectic (LBE) is the preferred coolant for LFRs. However, LBE with high temperature, high density, and high flow rate will cause intensive corrosion towards the reactor structural materials, which poses a threat to the operational safety of reactors. 304L stainless steel is a candidate structural material for this reactor, and arc additive manufacturing is a novel way to alternate the microstructure of this steel. Therefore, this paper focuses in the influence of δ-ferrite generated in the wire arc additive manufactured (WAAM) 304L stainless steel on its corrosion behavior in saturated oxygen/poor oxygen liquid LBE at 550 ^oC. The results reveal that the corrosion resistance of δ-ferrite is superior to that of austenite. A spinel Fe-Cr protective oxide scale may form on the peripheries of δ-ferrites, which hinder the inward growth of the oxide scale. Consequently, a pincer-like morphology of oxide scale developed within the internal oxidation zone. In poor-oxygen LBE, WAAM 304L stainless steel mainly undergoes dissolution corrosion. Despite a Cr-rich protective scale cannot be formed on its surface due to oxygen content limitations, thereby failing to effectively inhibit dissolution corrosion, even so δ-ferrite still exhibits great resistance to dissolution corrosion. This is mainly attributed to the low Ni content in δ-ferrite, whereas dissolution corrosion is primarily controlled by the dissolution of Ni element.