TY - JOUR
T1 - Numerical study of the metal vapour transport in tungsten inert-gas welding in argon for stainless steel
AU - Xiang, Junting
AU - Chen, Fiona F.
AU - Park, Hunkwan
AU - Tanaka, Keigo
AU - Shigeta, Masaya
AU - Tanaka, Manabu
AU - Murphy, Anthony B.
N1 - Funding Information:
JX thanks the CSIRO Research Plus Postdoctoral Fellowship scheme for support of this work. HP acknowledges the support from the Fundamental Research Program (No. PNK6350) of the Korea Institute of Materials Science (KIMS). KT, MS and MT acknowledge the support of the Structural Materials for Innovation of the Cross-ministerial Strategic Innovation Promotion Program (SIP) of Japan Science and Technology Agency.
Funding Information:
JX thanks the CSIRO Research Plus Postdoctoral Fellowship scheme for support of this work. HP acknowledges the support from the Fundamental Research Program (No. PNK6350) of the Korea Institute of Materials Science (KIMS). KT, MS and MT acknowledge the support of the Structural Materials for Innovation of the Cross-ministerial Strategic Innovation Promotion Program (SIP) of Japan Science and Technology Agency.
Publisher Copyright:
© 2019
PY - 2020/3
Y1 - 2020/3
N2 - Metal vapour emanating from the weld pool during tungsten-inert-gas (TIG) welding affects the arc welding process. To understand the transport mechanisms of metal vapour in a TIG arc, an axisymmetric computational model is developed that includes the tungsten cathode, stainless-steel anode workpiece and the arc plasma region self-consistently. The combined diffusion coefficient method, which calculates diffusion coefficients due to mole fraction gradients (ordinary diffusion), temperature gradients, pressure gradients and the electric field is used to treat iron–chromium–argon and iron–chromium–helium plasmas. It was found that in both cases, metal vapours can reach the cathode region. The effect of different diffusion coefficients on metal vapour transport was investigated. It was found that ordinary diffusion is the main driving force for upward metal vapour diffusion away from the anode workpiece in an argon arc. The diffusive transport carries the metal vapour into the recirculating convective flow, which then transports the metal vapour to the cathode region. Here the upward diffusion driven by the temperature gradient and electric field leads to the build of high concentrations of the metal vapours adjacent to the cathode. In the helium arc, in contrast, metal vapour is transported upwards from the workpiece by electric field diffusion, which is much stronger in this case. Spectroscopic measurements of atomic chromium emission show that metal vapour can reach the cathode region in an argon TIG arc, providing support for the predictions of the model. Only by taking into account all diffusion driving forces is it possible to predict the distribution of metal vapour in a TIG welding arc.
AB - Metal vapour emanating from the weld pool during tungsten-inert-gas (TIG) welding affects the arc welding process. To understand the transport mechanisms of metal vapour in a TIG arc, an axisymmetric computational model is developed that includes the tungsten cathode, stainless-steel anode workpiece and the arc plasma region self-consistently. The combined diffusion coefficient method, which calculates diffusion coefficients due to mole fraction gradients (ordinary diffusion), temperature gradients, pressure gradients and the electric field is used to treat iron–chromium–argon and iron–chromium–helium plasmas. It was found that in both cases, metal vapours can reach the cathode region. The effect of different diffusion coefficients on metal vapour transport was investigated. It was found that ordinary diffusion is the main driving force for upward metal vapour diffusion away from the anode workpiece in an argon arc. The diffusive transport carries the metal vapour into the recirculating convective flow, which then transports the metal vapour to the cathode region. Here the upward diffusion driven by the temperature gradient and electric field leads to the build of high concentrations of the metal vapours adjacent to the cathode. In the helium arc, in contrast, metal vapour is transported upwards from the workpiece by electric field diffusion, which is much stronger in this case. Spectroscopic measurements of atomic chromium emission show that metal vapour can reach the cathode region in an argon TIG arc, providing support for the predictions of the model. Only by taking into account all diffusion driving forces is it possible to predict the distribution of metal vapour in a TIG welding arc.
KW - Diffusion coefficient
KW - Metal vapour
KW - Spectroscopic measurements
KW - Tungsten inert-gas welding
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U2 - 10.1016/j.apm.2019.11.001
DO - 10.1016/j.apm.2019.11.001
M3 - Article
AN - SCOPUS:85076220873
VL - 79
SP - 713
EP - 728
JO - Applied Mathematical Modelling
JF - Applied Mathematical Modelling
SN - 0307-904X
ER -