The effect of pre-heating and pre-cold treatment on the formation of liquation and solidification cracks of nickel-based superalloy welded by laser beam

Chen, Zhuoyi; Taheri, Morteza

doi:10.1016/j.jmrt.2020.07.053

Cited by 28 publications

(4 citation statements)

References 23 publications

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“…The temperature of this heat source is estimated at about 900 °C-1000 °C [18]. Several results have shown that with increasing the preheating temperature, the absorption of the laser beam will increase and as a result, the melting rate will increase [19,20]. In the study of the melting rate of ST14 steel by sabbaghzadeh and et al [21], with the increase of welding speed from 30 to 69 cm min −1 , the melting rate decreased from 80% to 55%.…”

Section: Resultsmentioning

confidence: 99%

Investigation of melting rate in welding of IN738 Nickel-based superalloy by Nd:YAG pulsed-laser method

et al. 2020

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In this study, the effect of different parameters of pulsed Nd:YAG laser welding, including pulse energy, pulse frequency, pulse duration, and welding speed on the melting rate of IN738 Nickel-based superalloy, was investigated. The results of this study were obtained based on the modification of a formula for calculating the melting rate of welding by pulse method (pulse overlap). According to this formula, effective pulse energy (EPE) affected by pulse overlap, has a significant effect on the melting rate. So that by decreasing the amount of EPE (increasing the pulse overlap), the melting rate increases to 67% overlap and then decreases due to the reduction of the heating rate through heat transfer to the base metal. The study of the effect of pulse laser parameters showed that pulse energy, pulse overlap, and pulse duration have the greatest effect on melting rate, respectively.

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Section: Resultsmentioning

confidence: 99%

Investigation of melting rate in welding of IN738 Nickel-based superalloy by Nd:YAG pulsed-laser method

et al. 2020

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“…[27]. These conditions represent an unexplored conditional combination between heat input and high-energy density, while recent previously mentioned studies approximately covered heat inputs from 25 to 220 J/mm and energy densities from 30 to 280 J/mm 2 [5,[15][16][17][18][19][20][21][22]. For the circular wobble welding, three levels of wobble frequency (10,15,20 kHz) were applied at each scan speed with 0.1 mm of wobble amplitude.…”

Section: Single-mode Fibre Laser Weldingmentioning

confidence: 99%

“…In this regard, applicability of laser welding technologies has been examined for 247LC [5] and other precipitation-hardened superalloys, which suffer from liquation cracking. These include Rene80 [14], Haynes282 [15], IN738LC [16], GH909 [17], GTD111 [18][19][20], IC10 [21], and K447A [22]. In fact, despite application of low heat input laser welding, almost no studies could achieve liquation crack-free welds, and the mechanisms of this process are still related to the diffusion-controlled reaction between matrix phases of base material with secondary phases, such as γ -γ ' eutectic, carbides, and borides.…”

Section: Introductionmentioning

confidence: 99%

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

Chun

Jeong

Kim

et al. 2023

Science and Technology of Welding and Joining

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Under completely suppressed constitutional liquation of MC carbide, unexplored 247LC superalloy single-mode fibre laser welds experience unexpected liquation cracking. These cracks continuously propagate from a solidification crack, particularly at highly misoriented and epitaxially grown solidification grain boundaries, and dominated by pipeline diffusion of impurities. Two novel metallurgical preconditions were identified which, if satisfied, ensure complete suppression of liquation cracking of 247LC superalloy welds. These preconditions are (i) the constitutional liquation of MC carbide at the heat-affected zone and (ii) pipeline diffusion of impurities at the fusion zone. It is also highly recommended that the welding is carried out in a single directionally solidified grain under scanning conditions, avoiding the formation of highly misoriented solidification grain boundaries.

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“…Meanwhile, IN738 nickel-based superalloy has always been the first choice for turbine blades in the electrical and aerospace industries due to its advantages such as impact resistance, oxidation, creep, corrosion, and fatigue [3,4]. The γ′ precipitation phase with Ni 3 (Ti, Al) chemical composition is the most important secondary phase of IN738, which provides suitable working conditions during casting and heat treatment, by precipitation in austenitic matrix [5,6]. Various studies have shown that the γ′ phase is the main factor of resistance to favorable mechanical conditions, especially impact resistance [7,8].…”

Section: Introductionmentioning

confidence: 99%

Characterization of fracture behavior of a nickel-based using Charpy instrumented in different conditions of heat treatment and evaluation temperatures

et al. 2021

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Since gas turbine blades work in acute conditions, the study of their mechanical behavior, including impact, is one of the most important tasks recommended. The aim of this study was to investigate the impact behavior of IN738 superalloy welded by pulsed laser under different heat treatment conditions and different temperatures. The results of this study showed that the lowest fracture toughness was related to the specimens that were welded under casting conditions. This was due to the formation of liquation cracks during welding and due to the reaction between the (Ti,Ta)C carbide, γ-γ′ eutectic, and γ′ phase with the superalloy matrix. As the test temperature increased from ambient temperature to 600 °C, the impact toughness increased. This is attributed to the free presence of dislocations, which causes ductile behavior in the alloy. As the temperature increased further to 770 °C, the fracture toughness increased due to the increased strength of the superalloy yield due to locking of dislocations. At temperatures above 770 °C, the toughness of the superalloy was reduced again due to the decrease in strength due to the passage of dislocations through the obstacles.

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The effect of pre-heating and pre-cold treatment on the formation of liquation and solidification cracks of nickel-based superalloy welded by laser beam

Cited by 28 publications

References 23 publications

Investigation of melting rate in welding of IN738 Nickel-based superalloy by Nd:YAG pulsed-laser method

Investigation of melting rate in welding of IN738 Nickel-based superalloy by Nd:YAG pulsed-laser method

Liquation crack-free welding strategy for 247LC DS superalloy by control of pipeline diffusion via ultra-high-speed laser beam scanning

Characterization of fracture behavior of a nickel-based using Charpy instrumented in different conditions of heat treatment and evaluation temperatures

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