Materials Science & Technology

Analysis of Arc Characteristics in Oxide Active TIG Welding Based on Spectroscopy Diagnosis

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  • 1.State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,Gansu,China
    2.Wenzhou Engineering Institute of Pump & Valve,Lanzhou University of Technology,Wenzhou 325100,Zhejiang,China
    3.School of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China
李春凯(1990-),男,副研究员,主要从事焊接过程传感及智能控制、焊接方法等的研究。

Received date: 2021-11-04

  Online published: 2022-03-15

Supported by

the National Natural Science Foundation of China(52005237);the Natural Science Foundation of Zhejiang Province(LQ21E050023);the Natural Science Foundation of Gansu Province(20JR10RA164)

Abstract

As a new welding method, active tungsten argon arc welding (A-TIG welding), which increases weld pe-netration and improves welding efficiency by coating active agent on the surface of base metal, has been widely used in actual production. As one of the most common active flux formulations in A-TIG welding, oxide’s influence mechanism for arc behavior is still in debate. In order to clarify the influence mechanism of oxide on the arc beha-vior of TIG welding, a synchronous acquisition system of arc morphology and arc spatial spectrum was established. The spectral line distribution and arc morphology characteristics of active agent particles, argon, iron and other charged particles in the arc spatial space under the action of oxide were studied, and the arc electron temperature in different regions was calculated based on Boltzmann mapping method. It is found that the relative intensity of Ar Ⅱspectral lines in the arc space decreases gradually with the increase of the distance from the cathode region. This is because the closer the arc is to the cathode region, the more concentrated the arc energy density is, the more favo-rable it is to promote the ionization of Ar atoms. SiO2 and B2O3 can promote the ionization of Ar particles, while TiO2 can inhibit the ionization of Ar particles. The distribution law of the relative intensity of Fe Ⅱ spectral lines in the axial direction is opposite to that of Ar Ⅱ spectral lines. The relative intensity of the spectral lines gradually decreases from the vicinity of the anode region to the vicinity of the cathode region. This is because the closer it is to the surface of the molten pool (near the anode region), the higher the concentration of iron vapor evaporated into the arc space is and the more obvious the ionization is. The introduction of three kinds of oxide active agents can reduce the relative intensity of Fe Ⅱ spectral lines. In the arc space coated with TiO2 active agent, no obvious Ti Ⅰcharacteristic line and arc contraction phenomenon were detected, and the arc temperature field did not change significantly, which means that the influence of TiO2 active agent on the arc behavior is very weak. The characteristic spectral lines of Si Ⅰ and B Ⅰ were detected in the arc space coated with SiO2 and B2O3 active agents, and the two active agents can cause arc contraction, but the arc contraction has no obvious effect on the arc temperature field.

Cite this article

LI Chunkai, DING Bin, SHI Yu, et al . Analysis of Arc Characteristics in Oxide Active TIG Welding Based on Spectroscopy Diagnosis[J]. Journal of South China University of Technology(Natural Science), 2022 , 50(8) : 128 -135 . DOI: 10.12141/j.issn.1000-565X.210699

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