Deformation-induced martensitic transformation in 316L stainless steels fabricated by laser powder bed fusion

摘要

Tensile deformation behavior of the 316L SS fabricated by laser powder bed fusion (LPBF) is revealed in this work and dislocation cells decorated with Cr/Mo segregation play a critical role in the microstructural evolution during deformation. Dislocation slips can initiate from the cell boundaries and later forming a cell/deformed twin intersection structure. Martensitic transformation can be favorable for the LPBF 316L SS under massive deformation (i.e., fracture site) at ambient temperature, the inhomogeneous elemental distribution leads to variable stacking fault energies (SFEs), and the martensite is proposed to initiate from the cell interior due to the low SFE thereof.