Study of heat affected zone for choosing suitable shielding and nozzle gas in plasma arc welding

Abstract

In this paper, the plasma arc welding (PAW) is studied and stainless steel temperature field is gained in this process. The thermal effect of plasma arc that specially depends on the plasma and shielding gases type and temperature field of it in work piece, which is the main key of analysis and optimization. Simulation of this process begins precisely and the separated fields for work piece, plasma arc, shielding gas and field for environment as well considered. These field equations are derived and process optimization is done by SIMPELC method and by ANSYS software coding. This simulation for gaining the temperature field of stainless steel, the effect of parameter variation on temperature field and process optimization for different cases of plasma and shielding gases (Argon, Helium and mixture of them), are done. Finally, the results of experimental tests are used to compare. The results that are derived from thermal fields show the affected process parameters which can be used for PAW process optimization. The numerical results show the timedependant distributions of arc pressure and current density, and heat transfer at the work piece surface are different from presumed Gaussian distributions in previous models.