Tailoring deformation-induced martensitic transformation through cellular engineering in laser powder bed fusion processed 316L stainless steel

Abstract

The microstructural effect of 316L stainless steel (SS) fabricated by laser powder bed fusion on deformation-induced martensitic transformation (DIMT) was investigated. Both opposing effects, i.e., disturbing/promoting DIMT were observed. While the cellular structure and low-angle grain boundaries reduce the DIMT rate by disturbing shear band formation, the high dislocation density can activate direct BCC martensite nucleation and accelerate the DIMT. This observation suggests that controlling the two competing effects is the key to cellular engineering using additive manufacturing. © 2024 Elsevier B.V.