Microstructure and properties of inconel 718 and AISI 416 laser welded joints

Ramkumar, K. Devendranath; Dev, Sidharth; Prabhakar, K. V. Phani; Rajendran, R.; Mugundan, K. Giri; Narayanan, S.

doi:10.1016/j.jmatprotec.2018.10.039

Cited by 72 publications

(12 citation statements)

References 26 publications

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“…Niobium forms hard and fragile Niobium carbide (NbC) to the grain boundaries which increase the risk of cracking, especially in oxygen rich environment. [16] This can be seen in figure 4 b as red. Closer images reveals that grain boundary has a lot of carbide formation which can be seen as dark spots in figure 5 a. Laves phases can be seen in figure 5 as small pure white formations [5,17].…”

Section: Resultsmentioning

confidence: 79%

The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints

Kivirasi,

Lindqvist,

Lipiäinen

et al. 2023

IOP Conf. Ser.: Mater. Sci. Eng.

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Additive manufacturing of metals is a way of producing high-quality end-use parts. Technical alloys, for example Inconel 718, can be used to obtain a lot of benefits for example wear, corrosion, and heat resistance. Laser welding of Inconel 718 is a standard process, but there is rather limited amount of information of welding of additively manufactured nickel superalloys to the additively manufactured stainless steel. The process parameters need to be considered in laser welding. Undesired microstructure can occur due to wrong heat input during the welding process. This study examines laser welding of additively manufactured Inconel 718-316L parts and the effects of the welding parameters to the quality of the weld by analysing microstructure from the heat affected zone. This is done to achieve better part quality more cost efficiently compared to traditionally produced parts and to optimize the welding parameters. It is not feasible to manufacture the full large structure with IN718 and AM could be used to manufacture just the functional parts of the assembly. Tests have shown that welding heat input and cooling time affect to the quality. Inconel 718 hardness decrease across the fused zone because of the mixing of different elements in the molten weld pool. Laser welding highlights cuboidal shaped niobium rich carbides throughout the material to the heat affected zone grain boundaries on Inconel side.

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Section: Resultsmentioning

confidence: 79%

The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints

Kivirasi,

Lindqvist,

Lipiäinen

et al. 2023

IOP Conf. Ser.: Mater. Sci. Eng.

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“…They also noted that the tensile cracking occurred according to heat input and transverse speed, which was responsible for the Laves phases and microfissuring. As the AISI 416 side of specimens ruptured, the tensile properties of Inconel 718 were obscure [41]. Elongation on all weld seams and failures are illustrated in Fig.…”

Section: Ultimate Tensile Test Resultsmentioning

confidence: 98%

The Effect of TIG Welding Parameters and Automatization for Non-Heat Treated Inconel 718 Sheets

2021

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Inconel 718 alloy is widely used in applications that require advanced strength properties especially at high temperature conditions. Combust room walls, exhaust parts, jet tribune blades and gas tribune equipment are the most known using areas. This alloy can be welded with various fusion welding methods, but TIG (Tungsten Inert Gas) welding is preferred since, it provides simply application, mobility and low cost. This study was aimed to clarify that how adjusting the welding parameters and welding automatically can help to achieve promising mechanical properties before heat treatments. The welding experiments were conducted on three different welding current values and attention was paid to provide full penetration for each condition. The results showed that the highest welding current value which did not cause welding defects lead to decrease heat input due to the high transverse speed usage. Moreover, by automatically welding, the heat input was decreased to a minimum level that provided excellent tensile strength and elongation properties. Dendrites turned to cellular from colon. Hazardous zones, such as HAZ and PMZ, narrowed down. The Laves phase ratio and grain size also decreased. Microhardness results confirmed these microstructure observations. The crack observations after tensile tests showed that failures were near HAZ in high-heat input conditions. However, failures were observed in FZ for low-heat input conditions. Additionally, ductile fracture and fracture similar to cleavage mechanisms were observed together due to adjusting the parameters and automatization.

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“…It has wide application in aero-engines due to its superior mechanical properties, corrosion and oxidation resistance at higher temperature and outstanding weldability [2]. The main impelling force for the development of this alloy is it's resistance to strain age cracking [3]. IN718 is a precipitation hardened superalloy, where Nb plays a key aspect in formation of the main strengthening precipitate i.e.…”

Section: Introductionmentioning

confidence: 99%

Reduction of ASZ size and enhancement of mechanical properties of TLP bonded IN718 joint using post bond heat treatment process

Tarai

Pal²,

Robi³

2023

Preprint

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Transient liquid phase (TLP) bonding can be used to join Inconel 718 superalloy because the bond properties are similar to the parent material properties and little melting of base material. Presence of centerline eutectic and boride precipitates in the microstructure of the TLP bonded Inconel 718 joints affects mechanical properties of the joints. The eutectics and borides should be minimized to enhance the mechanical properties of the bond. This can be achieved to a great extent by prolonged isothermal holding. However, it can induce adverse effects by modifying the microstructure of the base material. Post bond heat treatment (PBHT) processes can be implemented to improve the mechanical properties without inducing any harmful effect of prolonged heating. In the present work, the effect of PBHT technique (i.e. solution treatment and double aging) on the microstructural evolution and improvement in mechanical properties were investigated. The ultimate tensile strength (UTS) and microhardness of TLP bond before and after the PBHT were analyzed and compared with the as-received workpiece. FESEM, FETEM and XRD analysis were used to quantify different precipitates formed during PBHT of TLP bond. The results showed that the PBHT improved the microstructure and mechanical properties of the bonded samples. After the solution treatment and double aging, a maximum UTS of 1210 MPa was obtained, which correspond to a 113.5% increase. The improvement of bond strength was attributed to increase volume fraction of γ' and γ" type strengthening phases during double aging and a decrease in the fraction of Nb-Mo type borides in the diffusion affected zone.

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Microstructure and properties of inconel 718 and AISI 416 laser welded joints

Cited by 72 publications

References 26 publications

The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints

The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints

The Effect of TIG Welding Parameters and Automatization for Non-Heat Treated Inconel 718 Sheets

Reduction of ASZ size and enhancement of mechanical properties of TLP bonded IN718 joint using post bond heat treatment process

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