Numerical analysis on nitrogen protecting of TIG welding arc

Nitrogen protecting tungsten inert gas(TIG) welding arc was studied.A mathematic model was developed according to the theory of magnetic fluid dynamics.The electrode tip geometry is consi-dered in the model,and the TIG welding arc was numerically analyzed based on this model.The calculated result of arc plasma temperature agrees with the experiment,and is compared with Ar protecting arc at the same condition.The arc pressure,current density distribution and velocity distribution were analyzed based on the model.The influences of the distribution of velocity of the arc plasma about different current and arc length are analyzed.The velocity increases with the increase of current and decreases with the increase of arc length.nitrogen protecting TIG welding;welding arc;magnetic fluid dynamics;numerical analysis