Characteristics of heat affected zone cracking in Inconel 718 cast alloy. Study of weldability of Inconel 718 cast alloy (1st Report)

Woo, Insu; Nishimoto, Kazutoshi; Tanaka, Kazuaki; Shirai, Makoto

doi:10.1080/09507110009549195

Cited by 11 publications

(7 citation statements)

References 6 publications

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“…the base material), which we determined in a previous study [3]. As-cast CM247LC alloy is far more susceptible to liquation cracking than other typical superalloys, such as alloys 690 [17] and 718 [21], which have LCTRs of 120 and 248 K. However, this poor cracking resistance can be improved by an ageing treatment; that is, the liquation cracking susceptibility can be reduced by controlling the micro-structure of the as-cast sample [3]. In fact, in the multi-pass welding experiments used in this study, the suppressed liquation cracking susceptibility of the aged base material increased significantly.…”

Section: Resultsmentioning

confidence: 99%

Liquation cracking susceptibility of remelted and reheated weld metals in CM247LC superalloy using multi-bead Varestraint testing

Chun

Jeong

Seo

et al. 2023

Science and Technology of Welding and Joining

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The liquation cracking temperature range (LCTR) of CM247LC was evaluated, especially in remelted and reheated weld metals produced during multi-pass repair welding. The LCTR of the remelted weld metal was 282 K, and those of the reheated weld metals were 455-805 K depending on the testing position. In the multi-bead within the reheated weld metal, the LCTR increased from 455 K far from the inter-pass boundary to 805 K near this boundary. The mechanism underlying the varying LCTR for the remelted and reheated weld metals was the amount of MC carbide at each weld position. The single-mode fibre laser welding suppressed the carbide within both areas, and lowered the liquation cracking susceptibility.

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Section: Resultsmentioning

confidence: 99%

Liquation cracking susceptibility of remelted and reheated weld metals in CM247LC superalloy using multi-bead Varestraint testing

Chun

Jeong

Seo

et al. 2023

Science and Technology of Welding and Joining

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“…3(b)) showed a fine and wavy pattern on the grain boundary facet indicating the presence of a thin liquid film prior to HAZ cracking. These phenomena clearly suggest that the cracks produced in the longitudinal Varestraint test are liquation cracking, which are the same as those previously reported for actual TIG welding [13]. The total crack length (TCL) in HAZ was measured and plotted as a function of grain size, as shown in Fig.…”

Section: Experimental Materials and Pro-ceduresmentioning

confidence: 88%

Metallurgical factors contributing to HAZ cracking susceptibility in cast alloy 718 welds and its improvement by cerium addition

Woo

Nishimoto

2001

Met. Mater. Int.

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A study was carried out to determine the effect of cerium addition on HAZ cracking susceptibility in cast alloy 718 welds. The cause of HAZ cracking was also investigated using commercial cast alloy 718 varying in grain size at three levels. The hot cracking test results for commercial cast alloy 718 indicated that the fine-grained alloy was less sensitive to HAZ cracking. Furthermore, cerium addition of up to 0.3 wt.% was found to have a beneficial effect in reducing HAZ cracking susceptibility. When cerium addition exceeds 0.3 wt.%, HAZ cracking susceptibility increased further. The mechanism of HAZ cracking was found to be related to intergranular liquation caused by the eutectic melting of sulfur containing a laves cluster at the grain boundaries. The degree of grain boundary liquation in the fine-grained specimen was less than that of the coarse-grained specimen due to a decrease in the amount of laves cluster and sulfur segregation in it at the grain boundaries, which seems to be responsible for a reduction in hot cracking susceptibility in the fine-grained specimen. Microscopic observation suggested that the improved HAZ cracking susceptibility in cerium containing alloy could be attributed to a reduction in the amount of laves cluster and sulfur segregation in it at grain boundaries due to the grain size reduction and sulfur-scavenging effects of cerium.

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“…Understanding the thermodynamic behavior of phase transformation and phase field will enhance the kinetic materials' properties control and solidification process [42][43][44][45]. The motivation stems from the need to develop the joining method to eliminate crack formation [46,47]. Furthermore, a need for strong bonding while controlling the melting zone and heat-affected zone (HAZ) yielded a shorter-time and inter-layer free process.…”

Section: Introductionmentioning

confidence: 99%

Solid-state diffusion bonding for INCONEl 617 superalloy using field-assisted sintering technology (FAST) guided by CALPHAD approach

Degnah,

Alnaser,

Kurdi

et al. 2024

Mater. Res. Express

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This study investigates solid-state diffusion bonding between two INCONEl 617 alloy samples using field-assisted sintering technology (FAST). The study focuses on analyzing the faying surface validating the theoretical alloy design modeling done by the CALculation of PHAse Diagrams (CALPHAD) approach followed by experimental validation. Varying kinetics’ limitations enabled phase stability and phase control governed by the CALPHAD approach alloy design. The alloy design contains a pseudo-binary phase diagram assisted with thermal mapping of a property phase diagram to obtain the optimum temperature of solid-state diffusion bonding while understanding phase fields and their evolution through Mo-increasing content and temperature increase. The FAST parameters recommended by CALPHAD were 800 °C under 10 MPa pressure with a holding time of 30 minutes. The investigation observations were promising where the faying surface contains γ only, while the further region on the alloy contains γ and γ`. It is worth mentioning that FAST advantage resulted in fine faying surface thickness of around 10 µm and a controlled heat affected zone (HAZ) leading to extreme reduction in recrystallization zone yielding an average grain size of 60-100 µm before and after diffusion bonding. Furthermore, two modes of metal carbide (MC) have been found, MC formed under the faying surface and micro-MC pools formed around the faying surface. 

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Characteristics of heat affected zone cracking in Inconel 718 cast alloy. Study of weldability of Inconel 718 cast alloy (1st Report)

Cited by 11 publications

References 6 publications

Liquation cracking susceptibility of remelted and reheated weld metals in CM247LC superalloy using multi-bead Varestraint testing

Liquation cracking susceptibility of remelted and reheated weld metals in CM247LC superalloy using multi-bead Varestraint testing

Metallurgical factors contributing to HAZ cracking susceptibility in cast alloy 718 welds and its improvement by cerium addition

Solid-state diffusion bonding for INCONEl 617 superalloy using field-assisted sintering technology (FAST) guided by CALPHAD approach

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