Wetting behavior of melt and its effect on lack of fusion in arc oscillating NG-GTAW

Li, Fuxiang; Sun, Qing; Jin, Peng; Liu, Yibo; Chen, Mingliang; Li, Junzhao; Hou, S.; Wang, Mingxin; Ji, Yongzhuang

doi:10.1016/j.jmatprotec.2021.117176

Cited by 15 publications

(7 citation statements)

References 22 publications

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“…The sidewall fusion quality significantly improved in laser-CMT-misaligned hybrid welding. When using arc welding alone for narrow gap welding, lack-of-fusion defects can be avoided by increasing the heat input, but a large HAZ will form [14]. When laser welding is used, a high machining accuracy of the groove is required, otherwise lackof-fusion defects will likely occur [21].…”

Section: Joint Microstructure and Microhardnessmentioning

confidence: 99%

“…However, the narrow gap poses certain challenges to the currently available welding methods, such as the restriction of the welding angle by the narrowness of the gap [13]. Li et al [14] used arc oscillating GTAW as the heat source in narrow gap welding, and indicated that the fusion defects can be reduced. However, the size of the heat affect zone (HAZ) increased.…”

Section: Introductionmentioning

confidence: 99%

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Narrow Gap Welding of X80 Steel Using Laser-CMT Hybrid Welding with Misaligned Laser and Arc

Zheng

et al. 2022

Crystals

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The feasibility of using laser–cold metal transfer (CMT) misaligned hybrid welding to join an X80 line-pipe steel in a narrow gap configuration was investigated. The laser beam interacted with the sidewall and its bottom at a small angle, while the CMT arc acted on the backside of the laser beam. The influence of the distance parameter between the laser spot and the tip of the welding wire on the formation and defects of the filled weld were investigated. Narrow gap bevel welds were performed, and the joints were tensile and had a satisfactory Charpy impact score. The tensile fracture is located in the base metal, and the impact fracture is a ductile fracture. Under this condition, the heat input could be efficiently reduced, preventing the formation of defects such as lack of fusion and reducing the number of pores. Additionally, welds with a narrow heat affect zone (HAZ) could be obtained. The results reveal that the hybrid process, as a low-heat input method, is suitable for narrow gap welding.

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Section: Joint Microstructure and Microhardnessmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Narrow Gap Welding of X80 Steel Using Laser-CMT Hybrid Welding with Misaligned Laser and Arc

Zheng

et al. 2022

Crystals

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“…Liu et al [37] pointed out that in WAAM, the arc oscillation could reduce the columnar and increase the equiaxed grains, which could improve the tensile properties. Li et al [38] built the plate wetting test in arc oscillating NG-GTAW. The result showed that, with arc oscillation, the wettability of melt on the plate is improved to some extent, which is of great help in eliminating sidewall fusion defects.…”

Section: Introductionmentioning

confidence: 99%

Effects of Oscillation Width on Arc Characteristics and Droplet Transfer in Vertical Oscillation Arc Narrow-Gap P-GMAW of X80 Steel

Liu

Xue

Zhou

et al. 2023

Metals

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In fields, such as oil and gas pipelines and nuclear power, narrow-gap welding has often been used for the connection of thick and medium-thick plates. During the welding process, a lack of fusion was prone to occur due to groove size limitations, seriously affecting the service safety of large structures. The vertical oscillation arc pulsed gas metal arc welding (P-GMAW) method was adopted for narrow-gap welding in this study. The influence of the oscillation width on arc morphology, droplet transfer behavior and weld formation during narrow-gap welding was studied. Oscillation widths from 0 to 4 mm were used to weld narrow-gap grooves with a bottom width of 6 mm. The results show that, in non-oscillation arc welding, the arc always presented a bell cover shape, and the droplet transfer was in the form of one droplet per pulse, while the sidewall penetration of the weld was relatively small, making it prone to a lack of fusion. With an increase in the oscillation width, the arc gradually shifted to the sidewall. The droplet transfer mode was a mixed transfer of large and small droplets, and the sidewall penetration continued to increase, which was conducive to the fusion of the sidewall. However, when the oscillation width was wider than 3 mm, it led to the phenomenon of the arc climbing to the sidewall, and the weld was prone to porosity, undercutting and other welding defects. The oscillation width has a major impact on the stability of the welding process in vertical oscillation arc narrow-gap welding.

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“…There are also many new welding techniques to control the weld morphology, of which weave arc, realized by controlling the left and right periodic weave of the welding gun, was considered to be the most suitable for weld control of surfacing forming [9][10]. In addition, the weaving GTAW (W-GTAW) welding gun has been applied to reduce the occurrence of magnetic bias blowing for the welding process of some di cult welding materials [11]. The arc of the W-GTAW proved to be able to homogenize welding heat input, control molten metal ow and prevent undercut, slag inclusion, poor fusion and other weld defects [12].…”

Section: Introductionmentioning

confidence: 99%

Effect of Process Parameters on Arc Behavior and Weld Formation in Weaving Gas Tungsten Arc Welding

Xie

Zhou

Nian

et al. 2023

J. of Materi Eng and Perform

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The arc welding with weaving has been used widely to obtain better weld quality by avoiding lack of side wall fusion and improve the weld e ciency by obtaining the wide weld bead. But the effect of weaving process parameter change on the weld is not clear. The aim of this work is to study the effect of process parameters on arc behavior and weld formation in Weaving Gas Tungsten Arc Welding(W-GTAW), those parameters include welding currents, tungsten electrode heights from the electrode tip to upper surface of workpiece, weave angles, weave speeds, and weave stop time on the left and right sides. The instantaneous arc shape and electrical signal data were collected by high-speed camera and electrical signal acquisition system respectively. Furthermore, the weld morphology was also systematically analyzed. This result shows that the bottom surface radius of the arc changed with weaving in the W-GTAW. When the weave speed increased to 0.40 × 10 -1 rad/s, the change of the radius was the least, with only 0.10 mm drift, and the difference between the arc forces in the middle and the two sides of the molten pool was smallest. Compared with the stability of each welding process, decreasing the tungsten electrode heights, weave angle and speed could signi cantly enhance the stability of welding. The forming coe cient of weld with a weave angle of 1.9° was 3.11, which might help reduce stress concentration and hot crack tendency of the weld. This shows that increasing reasonable the weave angle and speed can increase the weld penetration from another point of view. Furthermore, the W-GTAW technology shows great application potential in weld forming control by adjusting process parameters.

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Wetting behavior of melt and its effect on lack of fusion in arc oscillating NG-GTAW

Cited by 15 publications

References 22 publications

Narrow Gap Welding of X80 Steel Using Laser-CMT Hybrid Welding with Misaligned Laser and Arc

Narrow Gap Welding of X80 Steel Using Laser-CMT Hybrid Welding with Misaligned Laser and Arc

Effects of Oscillation Width on Arc Characteristics and Droplet Transfer in Vertical Oscillation Arc Narrow-Gap P-GMAW of X80 Steel

Effect of Process Parameters on Arc Behavior and Weld Formation in Weaving Gas Tungsten Arc Welding

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