A comparison on metallurgical behaviors of 316L stainless steel by selective laser melting and laser cladding deposition

Stacking Fault Energy Analyses of Additively Manufactured Stainless Steel 316L and CrCoNi Medium Entropy Alloy Using In Situ Neutron Diffraction

“…1(b)), the DED process was performed using a laser power of 380-400 W, a scanning speed of 14.1 mm/s, a powder feeding rate of 0.042 g/sec, a layer thickness of 250 μm, and a hatch spacing (laser beam spot size) of 400 μm under argon gas atmosphere with a pressure of 10 mbar and an oxygen of 0.2%, Table S2. The energy density (E = P/dv, where P is the power, d is the hatch pitch, v is the scanning speed) is about 71 J/mm 2 and categorized to the middle-size DED process 29 . The scanning strategy was the orthogonal scan, which is firstly scanned with the vector along LD and secondly along TD starting from the same location among layers as shown in Fig.…”

“…Such higher cooling rates of AM process can provide significantly different microstructural characteristics such as fine grains, directional grain architectures, and non-equilibrium phases/composition substructures compared to the conventional casting process (~0.1-10 K/s) [26][27][28] . As a result, several studies have reported higher yield strengths and comparable elongations compared to cast or wrought forms in AM stainless steels (SS) [27][28][29][30] . Pham et al reported extraordinary high yield strength of 520 MPa and elongation of ~60% in PBF AM SS 316 L (double of annealed commercial SS 316 L alloys) and highlighted fine subgrains having high dislocation density and strong twinning-induced plasticity 28 .…”

Twinning induced plasticity in austenitic stainless steel 316L made by additive manufacturing

“…Although there are several studies on the mechanical behaviour and microstructures of 316L steel made by additive manufacturing [4,6,[8][9][10][11], it is surprising that the evolution of as-built microstructures after deformation has not been studied to help explain outstanding properties of AM 316L despite the high levels of porosity were often seen in printed samples. It is widely agreed that 316L made by AM has good elongation and a high yield strength which is significantly higher than that of annealed 316L.…”

“…However, there might be more than one reason for the extraordinary high yield strength of AM 316L. For example, the grain size was believed to be responsible for the macroscopically high yield strength [11]. More detailed studies need to be done to see if there are any other reasons for the high yield strength, in particular microstructures in grains after solidification.…”

On Microstructure and Corrosion Properties of Selective Laser Melted 316L Stainless Steel

“…Comparing with conventional manufacturing processes, such as casting or forming, this technology provides many advantages including fabrication of metallic parts with more complex shapes, less time from design stage to manufacturing, no need to post processing, and lower wastage precursors. In this technology, without the usage of specialized molds or tools, in a single step process, 3D components are fabricated through layer-wise addition of melted/sintered precursors powder on the substrate or previous layers, based on their digitally defined Computer Aided Design (CAD) data [1][2][3][4][5][6]. In recent years, various laser-based additive manufacturing methods for fabrication of metallic components have been developed, such as laser engineered net shaping (Lenz), direct metal deposition (DMD), laser solid forming (LSF), direct laser fabrication (DLF), laser metal deposition shaping (LMDS), direct metal laser sintering (DMLS), and selective laser melting (SLM) [1,5,7].…”