Damage characteristics of selective laser melted 304L stainless steel under Xe ion irradiation

Abstract

BackgroundOwing to its excellent mechanical properties and corrosion resistance, 304L stainless steel is widely used as the core structure material in advanced nuclear power systems.PurposeThis study aims to investigate the damage characteristics of selective laser melted (SLM) 304L stainless steel under Xe ion irradiation and compare them with that of traditionally manufactured (TM) 304 stainless steel under the same experimental conditions.MethodsSLM 304L and TM 304L alloy samples were irradiated with 5 MeV Xe ions at 550 ℃. The irradiation dose was 3.53×1015 ions·cm-2. The microstructure and nano-hardness changes of the both alloy samples before and after irradiation were characterized by transmission electron microscopy (TEM) and nanoindentation, respectively. TEM samples were prepared by focused ion beam.ResultsThe TEM images show that dislocation loops and bubbles appeared in the irradiated alloy samples. The average sizes and number densities of dislocation loops in the SLM 304L and TM 304L alloy samples are (2.13±0.53) nm and (1.94±0.46) nm, 1.48×1022 m-3 and 6.94×1022 m-3, respectively. The average sizes and number densities of Xe bubbles in the SLM 304L and TM 304L alloy samples are (3.71±1.40) nm and (1.37±0.46) nm, 3.50×1022 m-3 and 1.73×1023 m-3, respectively. The both alloy samples show the irradiation hardening after Xe ion irradiation. The irradiation hardening degrees of the SLM 304L and TM 304L alloy samples are 14% and 32%, respectively.ConclusionsThe calculation results based on the dispersed barrier hardening model (DBH) reveal that the dislocation loops and Xe bubbles caused by irradiation play an important role in irradiation hardening of the two kinds of alloys.

Keywords

• slm 304l stainless steel
• xe ion irradiation
• microstructure
• irradiation hardening