The Numerical Simulation Research On The Protective Effects Of Plasma Arc Welding

Plasma arc welding has the character of high depth-to-width ratio and good welding quality, the workpiece can be penetrated directly by this way. This method can achieve the result of one-side welding with back formation. So, this method has wide applications in many areas such as shipbuilding and aerospace industry. Welding torch is the key technology of plasma arc welding, it's the basis of achieving perfect welding quality. The design of plasma arc welding torch still stays in the imitation or empirical stage in our country, this method is not scientific enough. The torch designed by this method is low-skilled, and the high quality welding torch still needs to be imported. On the basis of the plasma arc welding torch provided by Suzhou Ahand Ltd, the shielding gas protective effect of the nozzle of the torch was simulated by the method of numerical simulation. The influence of flux of shielding gas, the ratio of plasma gas and shielding gas, distance between the nozzle of torch and workpiece, position of shielding gas cup and structure of the nozzle on the flow field was simulated. The changing regularity of the state of flow field with the change of these parameters was summarized. The simulation result provided some theoretical basis for the formulation of technological parameters and the design of welding torch. The method of"Computer Simulation Assist the Design of Welding Torch"can also be used for the torch design of plasma spray, gas tungsten arc welding and gas metal arc welding et al.