scholarly journals Influences of Horizontal and Vertical Build Orientations and Post-Fabrication Processes on the Fatigue Behavior of Stainless Steel 316L Produced by Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4203 ◽  
Author(s):  
Paul Wood ◽  
Tomasz Libura ◽  
Zbigniew L. Kowalewski ◽  
Gavin Williams ◽  
Ahmad Serjouei
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Shot Peening ◽  
Fatigue Behavior ◽  
Fracture Pattern ◽  
Fatigue Properties ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Test Pieces ◽  
Laser Systems

In this paper, the influences of build orientation and post-fabrication processes, including stress-relief, machining, and shot-peening, on the fatigue behavior of stainless steel (SS) 316L manufactured using selective laser melting (SLM) are studied. It was found that horizontally-built (XY) and machined (M) test pieces, which had not been previously studied in the literature, in both stress-relieved (SR) or non-stress-relieved (NSR) conditions show superior fatigue behavior compared to vertically-built (ZX) and conventionally-manufactured SS 316L. The XY, M, and SR (XY-M-SR) test pieces displayed fatigue behavior similar to the XY-M-NSR test pieces, implying that SR does not have a considerable effect on the fatigue behavior of XY and M test pieces. ZX-M-SR test pieces, due to their considerably lower ductility, exhibited significantly larger scatter and a lower fatigue strength compared to ZX-M-NSR samples. Shot-peening (SP) displayed a positive effect on improving the fatigue behavior of the ZX-NSR test pieces due to a compressive stress of 58 MPa induced on the surface of the test pieces. Fractography of the tensile and fatigue test pieces revealed a deeper understanding of the relationships between the process parameters, microstructure, and mechanical properties for SS 316L produced by laser systems. For example, fish-eye fracture pattern or spherical stair features were not previously observed or explained for cyclically-loaded SLM-printed parts in the literature. This study provides comprehensive insight into the anisotropy of the static and fatigue properties of SLM-printed parts, as well as the pre- and post-fabrication parameters that can be employed to improve the fatigue behavior of steel alloys manufactured using laser systems.

Physical properties and microstructure study of stainless steel 316L alloy fabricated by selective laser melting

2017 ◽  
Author(s):  
Nurul Kamariah Md Saiful Islam ◽  
Wan Sharuzi Wan Harun ◽  
Saiful Anwar Che Ghani ◽  
Mohd Asnawi Omar ◽  
Mohd Hazlen Ramli ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Physical Properties ◽  
Selective Laser Melting ◽  
Stainless Steel 316L ◽  
Laser Melting

Metallographic evaluation of duplex stainless steel powders processed by selective laser melting

2017 ◽  
Vol 23 (6) ◽  
pp. 1146-1163 ◽  
Author(s):  
Karl P. Davidson ◽  
Sarat B. Singamneni
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Selective Laser Melting ◽  
A Priori ◽  
Fine Tuning ◽  
Structure Property ◽  
Laser Melting ◽  
Content Type ◽  
Test Pieces ◽  
Process Structure

Purpose This paper aims to establish the microstructures and the process-structure relationships in duplex stainless steel powders consolidated by selective laser melting (SLM). Design/methodology/approach A priori data on energy density levels most appropriate to consolidation of duplex stainless steel powders through SLM served as the basis to converge on the laser settings. Experimental designs with varying laser power and scan speeds and test pieces generated allowed metallographic evaluations based on optical and scanning electron microscopy and electro backscatter diffraction analyses. Findings Duplex stainless steel powders are established for processing by SLM. However, the dynamic point heat source and associated transient thermal fields affect the microstructures to be predominantly ferritic, with grains elongated in the build direction. Austenite precipitated either at the grain boundaries or as Widmanstätten laths, whereas the crystallographic orientations and the grain growth are affected around the cavities. Considerable CrN precipitation is also evidenced. Originality/value Duplex stainless steels are relatively new candidates to be brought into the additive manufacturing realm. Considering the poor machinability and other difficulties, the overarching result indicating suitability of duplex powders by SLM is of considerable value to the industry. More significantly, the metallographic evaluation and results of the current research allowed further understanding of the material consolidation aspects and pave ways for fine tuning and establishment of the process-structure-property relationships for this important process-material combination.

Effects of Process Parameters on the Surface Roughness of Stainless Steel 316L Parts Produced by Selective Laser Melting

2018 ◽  
Vol 46 (4) ◽  
pp. 20170140 ◽  
Author(s):  
Derahman Nur Aqilah ◽  
Ab Karim Mohd Sayuti ◽  
Yusof Farazila ◽  
Dambatta Yusuf Suleiman ◽  
Mohd Amran Nor Amirah ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Stainless Steel 316L ◽  
Laser Melting

scholarly journals Selective laser melting of stainless steel 316L with low porosity and high build rates

2016 ◽  
Vol 104 ◽  
pp. 197-204 ◽  
Author(s):  
Zhongji Sun ◽  
Xipeng Tan ◽  
Shu Beng Tor ◽  
Wai Yee Yeong
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Low Porosity

Optimal Scanning Condition of Selective Laser Melting Processing with Stainless Steel 316L Powder

2011 ◽  
Vol 341-342 ◽  
pp. 816-820 ◽  
Author(s):  
Apinya Laohaprapanon ◽  
Pongnarin Jeamwatthanachai ◽  
Marut Wongcumchang ◽  
Nattapon Chantarapanich ◽  
Surapon Chantaweroad ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Visual Inspection ◽  
Processing Condition ◽  
Density Measurement ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Optimal Processing

This study aimed to investigate the stainless steel 316L processing by means of selective laser melting (SLM). The processing parameters under consideration included laser power (25-225 W), scanning speed (50-320 mm/s), and scan spacing (0.04 and 0.06 mm). Every processing was constrained the layer thickness as of 100 µm. All parameters were performed based on two experiments, line scanning and multiple layers scanning. Each of final workpieces was examined by visual inspection, density measurement, hardness, and built rate. From the experiments, the optimal processing conditions which produced the smooth tracks were obtained. The workpiece processed by this optimal processing condition presented quality characteristics with 97.6% density and 220±6 HV hardness.

Low-Cycle-Fatigue Properties of a 17-4 PH Stainless Steel Manufactured via Selective Laser Melting

2021 ◽  
Vol 877 ◽  
pp. 55-60
Author(s):  
Lorenzo Maccioni ◽  
Eleonora Rampazzo ◽  
Filippo Nalli ◽  
Yuri Borgianni ◽  
Franco Concli
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Low Cycle Fatigue ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Laser Melting ◽  
Softening Behavior ◽  
The One ◽  
Cylindrical Samples

In this paper, the static and low-cycle-fatigue (LCF) behavior of wrought samples of 17-4 PH stainless steel (SS) manufactured via Selective Laser Melting (SLM) are presented. On the one hand, several scholars have studied SLM materials and literature reports a huge amount of data as for the high-cycle-fatigue (HCF) behavior. On the other hand, few are the data available on the LCF behavior of those materials. The aim of the present research is to provide reliable data for an as-build 17-4 PH steel manufactured via SLM techniques. Only with quantitative data, indeed, it is possible to exploit all the advantages that this technology can offer. In this regard, both quasi-static (QS) and low-cycle-fatigue tests were performed on Additive Manufacturing (AM) cylindrical samples. Through QS tests, the constitutive low has been defined. Strain-controlled fatigue tests on an electromechanical machine were performed on 12 samples designed according to the ASTM standard. Tests were continued also after the stabilization was reached (needed for the cyclic curve described with the Ramberg-Osgood equation) to obtain also the fatigue (ε-N) curve. Results show that the material has a softening behavior. The Basquin-Coffin-Manson (BCM) parameters were tuned on the basis of the ε-N combinations after rupture.

Metallic Materials Prepared by Selective Laser Melting: Part Orientation Issue

2018 ◽  
Vol 779 ◽  
pp. 165-173
Author(s):  
Michaela Fousova ◽  
Drahomír Dvorský ◽  
Pavel Lejček ◽  
Dalibor Vojtěch
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Metallic Materials ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Individual Effects ◽  
Oriented Samples ◽  
Part Orientation ◽  
Melting Part

This paper shows part orientation issue in the process of Selective Laser Melting (SLM) at four examples of metallic materials (Fe, stainless steel 316L, TiAl6V4 alloy and AlSi11Mg alloy). Horizontally and vertically oriented samples differ in their mechanical properties, especially in plasticity. The causes of these differences are related to a thermal history, microstructural features and porosity. Depending on a particular material, individual effects are manifested under different extents.

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