Damage behavior of additive manufacturing 316L stainless steel irradiated with Fe ions

The irradiation damage behavior of 316L stainless steel (SS) fabricated using selective laser melting (SLM) and traditional manufacturing (TM) was investigated in terms of microstructural changes in hardness and swelling at RT under irradiation with 3 MeV Fe ions at doses of 0.3 to 6 dpa. At a dose of 6 dpa, the swelling heights of the SLM and TM samples were 39.1 nm and 30.7 nm, respectively, corresponding to swelling rates of 3.0 % and 2.4 %. The irradiated SLM 316L SS exhibited a lower degree of hardening at continuous fluences than the TM 316L SS. At a dose of 6 dpa, the hardening rates of the SLM and TM 316L SS specimens were 102.1 % and 84.1 %, respectively. Furthermore, TEM results showed that the density of dislocation loops in the TM 316L SS was 8.36 × 1023/m3 while that in the SLM 316L SS was 6.15 × 1023/m3. The average sizes of the dislocation loops were 1.35 and 1.22 nm, respectively. According to calculations using the dispersed barrier hardening (DBH) model, the dislocation loops were the primary factor influencing the irradiation hardening behavior. Under Fe-ion irradiation at RT, SLM 316L SS showed superior resistance to irradiation hardening and swelling compared with TM 316L SS.