| Summary: | To accurately simulate the plasma arc (PA) behavior in a wide current range, a steady two-dimensional model for the numerical calculation of the axisymmetric PA considering the high temperature cathode region (HTCR) was proposed. Based on the experimentally measured HTCR area, two distribution forms, namely, the mean value method and the Gaussian distribution method, were used to simulate the current density distribution behavior in the tungsten tip. The two proposed current densities were compared with the average current density model with a fixed discharge region. The Gaussian distribution form was chosen after a comprehensive comparison of experimental measured data and simulation data in aspects of arc pressure, electron temperature, and arc voltage at a welding current of 120 A. The model was verified to be accepted in a current range of 110–170 A by comparing the simulated and measured peak arc pressure values. The model has higher prediction accuracy over the common plasma arc model with the unchanged tip cathode, extends the prediction current range, and provides a tool for optimizing the nozzle structure and process parameters.
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