Radiation damage and irradiation-assisted stress corrosion cracking of additively manufactured 316L stainless steels

Abstract

The irradiation-induced microstructure and irradiation-assisted stress corrosion cracking (IASCC) behavior of additively manufactured (AM) 316L stainless steels produced by laser powder bed fusion were evaluated for the first time. Irradiation-induced dislocation loops, voids, and γ′ precipitates were observed in all processing conditions following 2.5 dpa at 360 °C. The cell structure and dense dislocation walls in the stress-relieved AM materials recovered and showed signs of recrystallization following irradiation. Anisotropy in both tensile property and IASCC susceptibility were observed in the stress-relieved AM 316L stainless steel due to the printing texture. The hot-isotropic pressed AM 316L had better radiation tolerance and lower IASCC susceptibility than the stress-relieved AM 316L and conventionally forged 316L. Therefore, post-printing hot-isotropic pressing (HIP) is recommended for enhancing radiation tolerance and IASCC performance in nuclear applications as it eliminates the anisotropic mechanical behavior and IASCC susceptibility associated with the printing texture.