Material-Specific Phenomena and Developing Higher Yield Process Parameters in Selective Laser Melting of 17-4 PH Stainless Steel

2021 ◽  
Author(s):  
EVREN YASA ◽  
İlker Atik ◽  
İpek Kandemir
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Chemical Composition ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Process Development ◽  
Industrial Applications ◽  
Full Density ◽  
Laser Melting ◽  
Quality Material

Abstract Although Selective Laser Melting has become attractive in industrial applications seeking a high geometrical complexity with short lead times and customization, some bottlenecks still exist for wider adoption. Build rate is one of them while the high number of process parameters and their interactions easily exceeding hundreds which affects the part performance is the second. The machine manufacturers supply parameter sets generally optimized for maximum density leading to good mechanical properties. However, other factors need to be considered in process development. This study aims at increasing the build rate of at least 2 times for 17-4 PH stainless steel without any significant effect on the density, surface quality, material composition, mechanical properties and residual stresses. The results show an excessive ultimate tensile strength to yield strength ratio in comparison to reported literature which is attributed to the double yield phenomenon mainly attributed to the phases present in the microstructure as a result of powder chemical composition and processing gas. Thus, it is concluded that powder chemical composition and processing gas are much more effective on the outcome while the process parameters with an increased build rate do not significantly change the results provided that almost full density is reached.

scholarly journals Microstructure and mechanical properties relationship of additively manufactured 316L stainless steel by selective laser melting

2019 ◽  
Vol 5 ◽  
pp. 23 ◽  
Author(s):  
Anne-Helene Puichaud ◽  
Camille Flament ◽  
Aziz Chniouel ◽  
Fernando Lomello ◽  
Elodie Rouesne ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
316L Stainless Steel ◽  
Hot Isostatic Pressing ◽  
Tensile Tests ◽  
Industrial Applications ◽  
Added Value ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties

Additive manufacturing (AM) is rapidly expanding in many industrial applications because of the versatile possibilities of fast and complex fabrication of added value products. This manufacturing process would significantly reduce manufacturing time and development cost for nuclear components. However, the process leads to materials with complex microstructures, and their structural stability for nuclear application is still uncertain. This study focuses on 316L stainless steel fabricated by selective laser melting (SLM) in the context of nuclear application, and compares with a cold-rolled solution annealed 316L sample. The effect of heat treatment (HT) and hot isostatic pressing (HIP) on the microstructure and mechanical properties is discussed. It was found that after HT, the material microstructure remains mostly unchanged, while the HIP treatment removes the materials porosity, and partially re-crystallises the microstructure. Finally, the tensile tests showed excellent results, satisfying RCC-MR code requirements for all AM materials.

scholarly journals Influence of the Energy Density for Selective Laser Melting on the Microstructure and Mechanical Properties of Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 919 ◽  
Author(s):  
Črtomir Donik ◽  
Jakob Kraner ◽  
Irena Paulin ◽  
Matjaž Godec
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Energy Density ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Material Properties ◽  
Beam Diameter ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
The Impact

We have investigated the impact of the process parameters for the selective laser melting (SLM) of the stainless steel AISI 316L on its microstructure and mechanical properties. Properly selected SLM process parameters produce tailored material properties, by varying the laser’s power, scanning speed and beam diameter. We produced and systematically studied a matrix of samples with different porosities, microstructures, textures and mechanical properties. We identified a combination of process parameters that resulted in materials with tensile strengths up to 711 MPa, yield strengths up to 604 MPa and an elongation up to 31%, while the highest achieved hardness was 227 HV10. The correlation between the average single-cell diameter in the hierarchical structure and the laser’s input energy is systematically studied, discussed and explained. The same energy density with different SLM process parameters result in different material properties. The higher energy density of the SLM produces larger cellular structures and crystal grains. A different energy density produces different textures with only one predominant texture component, which was revealed by electron-backscatter diffraction. Furthermore, three possible explanations for the origin of the dislocations are proposed.

scholarly journals Comparison of Vacuum Sintered and Selective Laser Melted Steel AISI 316L

2017 ◽  
Vol 62 (4) ◽  
pp. 2125-2131 ◽  
Author(s):  
Z. Brytan
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Selective Laser Melting ◽  
Strength Properties ◽  
Laser Melting ◽  
Charpy Test ◽  
Steel Type ◽  
Type 316L ◽  
Static Tensile

AbstractThe paper presents the results of the basic mechanical properties determined in the static tensile test, impact un-notched Charpy test and hardness of austenitic stainless steel type 316L produced by two techniques: classical pressing and sintering in a vacuum with rapid cooling and selective laser melting (SLM). In this work fracture surface of Charpy test, samples were studied.The results indicate that application of selective laser melting (SLM) makes it possible to double increase the strength properties of components manufactured from austenitic stainless steel type 316L compared to sintering in a vacuum. Resulted in mechanical properties strongly depend on porosity characteristic and the presence of superficial oxides in the case of sintered steel and the character of observed microstructural defects deriving from non-fully melted powder particles and the formation of voids between subsequently melted pool tracks during the SLM.

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