Effects of in-process LN2 cooling on the microstructure and mechanical properties of type 316L stainless steel produced by wire arc directed energy deposition

Cunningham, Chloe; Dhokia, Vimal; Shokrani, Alborz; Newman, Stephen T.

doi:10.1016/j.matlet.2020.128707

Cited by 33 publications

(9 citation statements)

References 10 publications

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“…Austenitic stainless steels (ASSs) can be used in a wide range of applications due to their properties, such as a good combination of strength and ductility and corrosion resistance [3]. The 316L grade is a type of ASS, which has attracted the attention of engineers and researchers in both academic and industrial areas [4]. Numerous studies have shown that L-PBF of 316L ASS results in a microstructure different from that of traditional 316L ASS, which can cause improved mechanical responses [5,6].…”

Section: Introductionmentioning

confidence: 99%

Effect of Hydrogen on the Tensile Behavior of Austenitic Stainless Steels 316L Produced by Laser-Powder Bed Fusion

Khaleghifar¹,

Razeghi²,

Heidarzadeh

et al. 2021

Metals

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Hydrogen was doped in austenitic stainless steel (ASS) 316L tensile samples produced by the laser-powder bed fusion (L-PBF) technique. For this aim, an electrochemical method was conducted under a high current density of 100 mA/cm2 for three days to examine its sustainability under extreme hydrogen environments at ambient temperatures. The chemical composition of the starting powders contained a high amount of Ni, approximately 12.9 wt.%, as a strong austenite stabilizer. The tensile tests disclosed that hydrogen charging caused a minor reduction in the elongation to failure (approximately 3.5% on average) and ultimate tensile strength (UTS; approximately 2.1% on average) of the samples, using a low strain rate of 1.2 × 10−4 s−1. It was also found that an increase in the strain rate from 1.2 × 10−4 s−1 to 4.8 × 10−4 s−1 led to a reduction of approximately 3.6% on average for the elongation to failure and 1.7% on average for UTS in the pre-charged samples. No trace of martensite was detected in the X-ray diffraction (XRD) analysis of the fractured samples thanks to the high Ni content, which caused a minor reduction in UTS × uniform elongation (UE) (GPa%) after the H charging. Considerable surface tearing was observed for the pre-charged sample after the tensile deformation. Additionally, some cracks were observed to be independent of the melt pool boundaries, indicating that such boundaries cannot necessarily act as a suitable area for the crack propagation.

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Section: Introductionmentioning

confidence: 99%

Effect of Hydrogen on the Tensile Behavior of Austenitic Stainless Steels 316L Produced by Laser-Powder Bed Fusion

Khaleghifar¹,

Razeghi²,

Heidarzadeh

et al. 2021

Metals

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“…Different approaches exist for active cooling. Reisgen et al [16] compared sprayed water with compressed air cooling at a wall geometry, and Cunningham et al [17] utilized liquid nitrogen to cool down a wall geometry. The cooling of parts manufactured by WAAM affects their mechanical properties.…”

Section: Waammentioning

confidence: 99%

Selective Paste Intrusion: Integration of Reinforcement by WAAM — Concept and Overview of the Current Research

Straßer¹,

Riegger²,

Hamilton³

et al. 2023

Preprint

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Selective Paste Intrusion (SPI) is an additive manufacturing (AM) process in which thin layers of aggregates are selectively bonded by cement paste only where the structure is to be produced. In this way, concrete elements with complex geometries and structures can be created. Reinforcement is required to increase the flexural strength of the concrete elements and, thus, enable their applicability in practice. Integrating the reinforcement is a difficult task, particularly in the case of SPI due to the layer-wise printing method. Especially with respect to possible complex structures, the production of the reinforcement needs to be adapted to SPI, thereby offering a high degree of freedom. One concept for a reinforcement integration is combining the two additive manufacturing processes SPI and Wire and Arc Additive Manufacturing (WAAM). However, since the two processes serve different fields of application, their compatibility is not necessarily given. Ongoing investigations show that the temperatures caused by WAAM adversely affect both, the cement paste rheology required for sufficient paste penetration into the particle bed and the overall concrete strength. This paper provides an overview of ongoing research focusing on different cooling strategies and their effects on the compressive strength of SPI-printed concrete parts.

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“…Selected Highlights [8] In-process cooling with liquid N 2 (cryogenic) GMA 1 and AISI 316L In-process cooling promoted grain refinement and improvement of mechanical properties.…”

Section: Thermal Management Approach Deposition Process and Materialsmentioning

confidence: 99%

“…In practice, heat accumulation is characterized by the consecutive increase in the part temperature during the manufacturing time [6]. In an extreme case, the heat accumulation can lead to the part's collapse [7], but before that it can cause problems of a metallurgical nature [8], geometric deviation [4], and excessive surface oxidation [9].…”

Section: Introductionmentioning

confidence: 99%

Effect of Thermal Management Approaches on Geometry and Productivity of Thin-Walled Structures of ER 5356 Built by Wire + Arc Additive Manufacturing

et al. 2021

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The present paper aimed at assessing the effect of two thermal management approaches on geometry and productivity of thin-walled structures built by Wire + Arc Additive Manufacturing (WAAM). Thin-walls of ER 5356 (Al5Mg) with different lengths and the same number of layers were deposited via the gas metal arc (GMA) process with the aid of an active cooling technique (near-immersion active cooling—NIAC) under a fixed set of deposition parameters. Then, the same experiment was performed with natural cooling (NC) in air. To characterize the thermal management approaches, the interpass temperature (i.e., the temperature at which subsequent layers are deposited) were monitored by a trailing/leading infrared pyrometer during the deposition time. Finally, thin walls with a fixed length were deposited using the NC and NIAC approaches with equivalent interpass temperatures. As expected, the shorter the wall length the more intense the deposition concentration, heat accumulation, and, thus, geometric deviation. This behavior was more evident and premature for the NC strategy due to its lower heat sinking effectiveness. The main finding was that, regardless of the thermal management technique applied, if the same interpass temperature is selected and maintained, the geometry of the part being built tends to be stable and very similar. However, the total deposition time is somewhat shorter with the NIAC technique due its greater heat sinking advantage. Thus, the NIAC technique facilitates the non-stop manufacturing of small parts and details via WAAM.

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Effects of in-process LN2 cooling on the microstructure and mechanical properties of type 316L stainless steel produced by wire arc directed energy deposition

Cited by 33 publications

References 10 publications

Effect of Hydrogen on the Tensile Behavior of Austenitic Stainless Steels 316L Produced by Laser-Powder Bed Fusion

Effect of Hydrogen on the Tensile Behavior of Austenitic Stainless Steels 316L Produced by Laser-Powder Bed Fusion

Selective Paste Intrusion: Integration of Reinforcement by WAAM — Concept and Overview of the Current Research

Effect of Thermal Management Approaches on Geometry and Productivity of Thin-Walled Structures of ER 5356 Built by Wire + Arc Additive Manufacturing

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