Preservation of Natural Phase Balance in Multi-pass and Wire Arc Additive Manufacturing-Made Duplex Stainless Steel Structures

2021 ◽  
Author(s):  
Farrokh Binesh ◽  
Alireza Bahrami ◽  
Mark Hebel ◽  
Daryush K. Aidun
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Duplex Stainless Steel ◽  
Steel Structures ◽  
Phase Balance ◽  
Wire Arc Additive Manufacturing

scholarly journals Wire-arc additive manufacturing of a duplex stainless steel: thermal cycle analysis and microstructure characterization

2019 ◽  
Vol 63 (4) ◽  
pp. 975-987 ◽  
Author(s):  
Vahid A Hosseini ◽  
Mats Högström ◽  
Kjell Hurtig ◽  
Maria Asuncion Valiente Bermejo ◽  
Lars-Erik Stridh ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Duplex Stainless Steel ◽  
Thermal Cycle ◽  
Microstructure Characterization ◽  
Wire Arc Additive Manufacturing

Additive manufacturing of 316L stainless-steel structures using fused filament fabrication technology: mechanical and geometric properties

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Miguel Ángel Caminero ◽  
Ana Romero ◽  
Jesús Miguel Chacón ◽  
Pedro José Núñez ◽  
Eustaquio García-Plaza ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Austenitic Stainless Steel ◽  
Material Properties ◽  
Steel Structures ◽  
Fused Filament Fabrication ◽  
Geometric Properties ◽  
Content Type ◽  
Build Orientation ◽  
Manufacturing Alternatives

Purpose Fused filament fabrication (FFF) technique using metal filled filaments in combination with debinding and sintering steps can be a cost-effective alternative for laser-based powder bed fusion processes. The mechanical behaviour of FFF-metal materials is highly dependent on the processing parameters, filament quality and adjusted post-processing steps. In addition, the microstructural material properties and geometric characteristics are inherent to the manufacturing process. The purpose of this study is to characterize the mechanical and geometric performance of three-dimensional (3-D) printed FFF 316 L metal components manufactured by a low-cost desktop 3-D printer. The debinding and sintering processes are carried out using the BASF catalytic debinding process in combination with the BASF 316LX Ultrafuse filament. Special attention is paid on the effects of build orientation and printing strategy of the FFF-based technology on the tensile and geometric performance of the 3-D printed 316 L metal specimens. Design/methodology/approach This study uses a toolset of experimental analysis techniques [metallography and scanning electron microcope (SEM)] to characterize the effect of microstructure and defects on the material properties under tensile testing. Shrinkage and the resulting porosity of the 3-D printed 316 L stainless steel sintered samples are also analysed. The deformation behaviour is investigated for three different build orientations. The tensile test curves are further correlated with the damage surface using SEM images and metallographic sections to present grain deformation during the loading progress. Mechanical properties are directly compared to other works in the field and similar additive manufacturing (AM) and Metal Injection Moulding (MIM) manufacturing alternatives from the literature. Findings It has been shown that the effect of build orientation was of particular significance on the mechanical and geometric performance of FFF-metal 3-D printed samples. In particular, Flat and On-edge samples showed an average increase in tensile performance of 21.7% for the tensile strength, 65.1% for the tensile stiffness and 118.3% for maximum elongation at fracture compared to the Upright samples. Furthermore, it has been able to manufacture near-dense 316 L austenitic stainless steel components using FFF. These properties are comparable to those obtained by other metal conventional processes such as MIM process. Originality/value 316L austenitic stainless steel components using FFF technology with a porosity lower than 2% were successfully manufactured. The presented study provides more information regarding the dependence of the mechanical, microstructural and geometric properties of FFF 316 L components on the build orientation and printing strategy.

scholarly journals Microstructure of laser metal deposited duplex stainless steel: Influence of shielding gas and heat treatment

2020 ◽  
Author(s):  
Maria Asuncion Valiente Bermejo ◽  
Karthikeyan Thalavai Pandian ◽  
Björn Axelsson ◽  
Ebrahim Harati ◽  
Agnieszka Kisielewicz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Nitrogen Loss ◽  
Steel Wire ◽  
Research Work ◽  
Shielding Gas ◽  
Austenite Content ◽  
Heat Treated ◽  
Phase Balance

AbstractThis research work is the first step in evaluating the feasibility of producing industrial components by using Laser Metal Deposition with duplex stainless steel Wire (LMDw). The influence of Ar and N2 shielding gases was investigated in terms of nitrogen loss and in the microstructure and austenite content of different deposited geometries. The evolution of the microstructure in the build-up direction of the Ar and N2-shielded blocks was compared in the heat-treated and as-deposited conditions. The susceptibility for oxygen pick-up in the LMDw deposits was also analyzed, and oxygen was found to be in the range of conventional gas-shielded weldments. Nitrogen loss occurred when Ar-shielding was used; however, the use of N2-shielding prevented nitrogen loss. Austenite content was nearly doubled by using N2-shielding instead of Ar-shielding. The heat treatment resulted in an increase of the austenite content and of the homogeneity in the microstructure regardless of the shielding gas used. The similarity in microstructure and the low spread in the phase balance for the as-deposited geometries is a sign of having achieved a stable and consistent LMDw process in order to proceed with the build-up of more complex geometries closer to industrial full-size components.

Evaluation of the Susceptibility of Duplex Stainless Steel 2205 to Hydrogen Assisted Cracking in REAC Systems

2016 ◽  
Author(s):  
Mei He ◽  
John Lippold ◽  
Boian Alexandrov ◽  
Jorge Penso
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Gas Tungsten Arc ◽  
Phase Balance ◽  
Hydrogen Assisted Cracking ◽  
Material Choice ◽  
Air Cooler ◽  
High Pressure Process ◽  
Process Fluid

Duplex stainless steel (DSS) is one material choice to fabricate the reactor effluent air cooler (REAC) of hydrocracker units in order to improve the performance and service lifetime of these units. Unfortunately, several failures from around the world have been reported in REAC units constructed of DSS, some within five years of service. Based on failure analysis reports, the failures were generally associated with welded joints and were caused by crevice/pitting corrosion and stress corrosion cracking. Given the condition of hydrogen-rich environment, high-pressure process fluid, and service temperature, this type of cracking is most likely a form of hydrogen assisted cracking (HAC). It is highly influenced by phase balance (ferrite/austenite) after welding and welding procedures, with high levels of ferrite in the weld metal or HAZ increasing the susceptibility to HAC. In this study, different weld metal phase balances were prepared by autogenous gas tungsten arc welding (GTAW). The delayed hydrogen cracking test (DHCT) was used to evaluate the effects of the weld phase balance on the susceptibility to HAC in DSS 2205 welds. Using this approach, weld metal ferrite levels on the order of 90 vol% ferrite led to very rapid failure, while reducing the ferrite level to approximately 60 vol% greatly increased resistance to HAC.

scholarly journals Tandem metal inert gas process for high productivity wire arc additive manufacturing in stainless steel

2019 ◽  
Vol 25 ◽  
pp. 545-550 ◽  
Author(s):  
Filomeno Martina ◽  
Jialuo Ding ◽  
Stewart Williams ◽  
Armando Caballero ◽  
Gonçalo Pardal ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Inert Gas ◽  
High Productivity ◽  
Wire Arc Additive Manufacturing
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