You-qi chuyun (Apr 2024)

Influence of welding torch nozzle structures on shielding gas flow field

  • LIANG Mingming,
  • LIU Xiaowen,
  • HOU Hao,
  • CHEN Jiaming,
  • NIU Lianshan,
  • JIANG Yanpeng

DOI
https://doi.org/10.6047/j.issn.1000-8241.2024.04.010
Journal volume & issue
Vol. 43, no. 4
pp. 449 – 456

Abstract

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[Objective] This paper seeks to address shortcomings in the conventional structural design of welding torch nozzles, such as prolonged development cycles, high costs, and uncertainty regarding the efficacy of shielding gas fow field protection. [Methods] The fuid dynamics computational software Fluent was utilized for numerical simulations, concentrating on critical parameters like shielding gas fow rates, welding torch nozzle structures, and nozzle-to-bevel spacings. The simulation results were subsequently verified and analyzed through gas dyeing experiments and practical welding operations. [Results] In the gas metal arc welding(GMAW) process context involving narrowgap bevels, a shielding gas fow rate of 20 L/min yielded effective protection to pipes. The conical nozzle and the fat conical nozzle presented ideal results in which the fat conical nozzle structure helped the shielding gas fow field obtain minimal conicity and straighter fow, fostering stable welding conditions by efficiently resisting crosswind disturbances at lower fow rates. Ensuring a nozzle-to-bevel spacing of less than 15 mm produced a shielding gas fow field with enhanced protection. The subsequent gas dyeing experiment and welding operations mirrored the simulation results on the fow field and welding performance of the conical nozzle and fat conical nozzle, affirming the feasibility of simulation methods for optimizing shielding gas fow fields. [Conclusion] The study findings showcase the effectiveness of fuid dynamic computation simulation technology in optimizing the structural design of welding torch nozzles and accelerating the development cycles, significantly improving the utilization efficiency of shielding gas in the GMAW welding process with narrow-gap bevels, and enhancing the stability of welding quality.By emphasizing the important role of simulation in welding process improvement, this paper offers new insights and technical references for the structural design of welding torch nozzles and the regulation of shielding gas fow fields.

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