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ORIGINAL RESEARCH article

Front. Mater.

Sec. Structural Materials

Volume 12 - 2025 | doi: 10.3389/fmats.2025.1634466

This article is part of the Research TopicJoining and Welding of New and Dissimilar Materials - Volume IIIView all 4 articles

Numerical Research on the Influence of Welding Gap on Arc Morphology in MAG Welding of AH36 Steel

Provisionally accepted
Jie  ShenJie Shen*Dayu  QiDayu QiRong  LaiRong LaiShuoyi  DuShuoyi Du
  • Shanghai Ocean University, Shanghai, China

The final, formatted version of the article will be published soon.

A numerical model of the three-dimensional MAG welding arc for a butt joint with AH36 Steel, incorporating both the welding gap and molten pool structures, was developed. The multi-physical characteristics of the MAG welding arc-including temperature, velocity, and pressure-were analyzed under steady-state conditions for welding gaps ranging from 0 to 2 mm using COMSOL 6.1 software. A detailed comparison of arc morphology under different welding gaps was conducted to explore the mechanism by which variations in the welding gap affect the arc morphology. The results show that the MAG welding arc morphology is basically symmetrically distributed in the direction of the weld cross-section. The arc width and the area of the arc are both consequently larger with increase of welding gap. When the welding current is 150 A and the gap expands from 0 mm to 2 mm, the arc width and area increase by 23.6% and 29.7% respectively. However, in the welding advance direction, the distribution of the arc form is asymmetric due to the presence of a molten pool structure behind the wire. the asymmetry and area of the arc becomes more significant with increase of welding gap. When the welding current is 150 A and the gap increases from 0 mm to 2 mm, the arc area grows by 53.9%, and the arc position drops by 0.29 mm. Finally, the accuracy of the model was validated by a highspeed video camera to capture the arc morphology during welding with varying welding gaps.

Keywords: MAG welding, Welding gap, Arc morphology, Arc characteristics, numerical simulation

Received: 24 May 2025; Accepted: 12 Aug 2025.

Copyright: © 2025 Shen, Qi, Lai and Du. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Jie Shen, Shanghai Ocean University, Shanghai, China

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