Effects of interfaces on the helium bubble formation and radiation hardening of an austenitic stainless steel achieved by additive manufacturing

Effects of Fe11+ Ions Irradiation on the Microstructure and Performance of Selective Laser Melted 316L Austenitic Stainless Steels

“…Figure 3a-b shows that the size and morphology of cellular sub-grains and nano-inclusions of post-irradiated samples remain relatively constant compared with those of pre-irradiated samples. The same findings were observed in SLM 316L SS irradiated by He ions at 450 • C [20]. According to previous studies, the ion irradiation could induce annealing in materials, and, subsequently, recrystallization [33,34].…”

“…However, the irradiation effect on SLM 316L SS is still unknown and has rarely been researched. In previous work, Sun et al performed the He ions irradiation experiments at 450 • C to demonstrate the internal effects of the microstructure on bubbles distribution and hardness of SLM 316L SS [20]. Song et al [21] performed Fe ions irradiation experiments at 360 • C to study the irradiation-induced microstructure and irradiation-assisted stress corrosion cracking (IASCC) behavior of AM 316L SS; the authors found that the hot-isotropic pressing (HIP) method could enhance the radiation tolerance and IASCC performance of the AM specimens.…”

Insight into structural stability and helium diffusion behavior of Fe–Cr alloys from first-principles

“…Sun et al produced 316L austenitic stainless steel by SLM method with He ion irradiation at 450 C. 3 The investigations reveal that the interface provided by subgrain boundaries and nano-oxide inclusions is an effective trapping point for He bubbles and helps to improve its tolerance. 4 Alloy 304 austenitic stainless steel is a standard "18/8 stainless steel", that is, stainless steel is mainly composed of Fe, Cr and Ni, 5 exhibits a face-centered cubic (fcc) austenite phase, [6][7][8] and the content of Cr and Ni is not less than 18% and 8% respectively. Alloy austenite can be obtained by adding Cr and Ni to g-Fe.…”

Response of solidification cellular structures in additively manufactured 316 stainless steel to heavy ion irradiation: anin situstudy

“…Note that these solidification cellular structures are not the same as conventional dislocation cell walls despite the morphology similarities [4]. Recently, there are increasing studies that explore the feasibility of applying AM 316 stainless steel (SS) as components for nuclear industry by judging their microstructure stability, mechanical properties, and corrosion sensitivity under high-temperature irradiation [8][9][10][11]. One major challenge is that the microstructure of metallic materials subjected to high-energy particle irradiation undergoes serious degradation, forming various types of defects, such as Frenkel pairs, dislocation loops, etc., which further undermine the mechanical properties of irradiated materials [12][13][14].…”

“…An effective way to mitigate irradiation-induced degradation in materials is to introduce high-density defect sinks [15], such as free surfaces [16], high angle grain boundaries [17,18], twin boundaries [19], and phase interfaces [20]. Recent ex situ proton and helium ion irradiation studies on AM 316 SS found that dense dislocations trapped inside solidification cellular structures tended to undergo recovery and recrystallization during radiation, and may serve as defect sinks, thus help alleviate void swelling and helium bubble formation [9,10]. However, studies on heavy ion irradiation of AM 316 SS with cellular structures remain scarce, and the underlying mechanisms of the microstructural evolution of cellular structures subjected to high-temperature irradiation are largely unknown.…”