Hardening behavior of selective laser melted 304L stainless steel under Xe irradiation

The irradiation damage behavior was studied in the Selective laser melted (SLM) 304L stainless steel irradiated by 5 MeV Xe ions at room temperature. The changes in the hardness and microstructure were characterized to explore the irradiation resistance of the SLM 304L stainless steel with traditionally manufactured (TM) 304L stainless steel as the reference material. The nanohardness results demonstrated that both investigated alloys exhibit irradiation hardening phenomena, with a lower hardening degree for irradiated SLM 304L stainless steel. At the ion dose of 10 dpa, the hardening degrees of the SLM and TM 304L stainless steel were 37% and 76%, respectively. Further the TEM results revealed the lower density and smaller dislocation loops appeared in SLM 304L stainless steel, which was caused by the unique dislocation wall at the sub-grain boundary, nano-inclusions, and fine grain structure. The calculated result based on the dispersed barrier hardening model revealed that the dislocation loop induced by irradiation was the dominant factor for the hardening of the materials.