Effect of post process shear straining on structure and mechanical \nproperties of 316 L stainless steel manufactured via powder bed fusion

0561191 - ÚFM 2023 RIV NL eng J - Journal Article
Kunčická, Lenka - Kocich, R. - Németh, Gergely - Dvořák, K. - Pagáč, M.
Effect of post process shear straining on structure and mechanical
properties of 316 L stainless steel manufactured via powder bed fusion.
Additive Manufacturing. Roč. 59, NOV (2022), č. článku 103128. ISSN 2214-8604. E-ISSN 2214-7810
R&D Projects: GA MŠMT LM2018111
Research Infrastructure: CANAM II - 90056; Reactors LVR-15 and LR-0 II - 90120
Institutional support: RVO:68081723 ; RVO:61389005
Keywords : Rotary swaging * Powder bed fusion * AISI 316 L * Stainless steel * Microstructure
OECD category: Materials engineering; Materials engineering (UJF-V)
Impact factor: 11, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S2214860422005176?via%3Dihub

Powder Bed Fusion (PBF) has become popular despite the fact that PBF-prepared components feature charac teristic defects. Their performance, however, can be shifted to the next level by the application of post processing, advantageously via intensive plastic deformation. The study characterizes the effects of rotary
swaging performed at hot, cold, and cryogenic conditions on the (sub)structure and mechanical properties of
workpieces of AISI 316 L stainless steel, favourably used in constructions as well as medicine, manufactured by
PBF. The workpieces built in the horizontal and vertical directions were analysed to assess their structures,
residual strain and stress, density, and porosity, porosity was observed primarily in the horizontally built
workpiece also featuring lower density and larger average grain size. Subsequently, the workpieces were sub jected to rotary swaging, which contributed to (almost) complete elimination of porosity, evident substructure
development, and significant grain refinement – the vertically built workpiece exhibited the avg. grain size of
2.3 µm, 1.8 µm, and 0.1 µm after hot, cold, and cryo swaging. The cryo-swaged sample also exhibited specific
texture, room temperature ultimate tensile strength (UTS) of more than 2 000 MPa, and two times higher
microhardness compared to the as-build workpiece. All the swaged pieces exhibited significantly improved
mechanical properties, even at the testing temperature of 900 ◦C.
Permanent Link: https://hdl.handle.net/11104/0334356