[1] Plasma transferred arc welding—modeling and experimental optimization. [J] J. Wilden, J. P. Bergmann & H. Frank.
[2] Microstructure and wear properties of nickel-based surfacing deposited by plasma transferred arc welding. [J] Chen Guoqing, Fu Xuesong, Wei Yanhui, Li Shan, Zhou Wenlong. 15 August 2013, Pages S276-S282.
The main arc in TPAW is established between the tungsten electrode and the guide electrode. Compared with non-transferred plasma arc welding (NPAW) where one of the arc terminals is a nozzle, the workpiece is not connected to the circuit, and the energy loss is less than NPAW.
As the welding current and plasma gas flow rate increase, the diameter of the ablation zone of the TPAW (ie, the energy received by the workpiece) is much larger than the diameter of the NPAW. The MZ area and HAZ area of the TPAW weld are smaller, but the penetration depth of the PAW weld is similar.
Under the same parameters, the MZ or HAZ cannot be observed in the NPAW weld, indicating that the total heat input distribution of TPAW is much larger than that of NPAW . This trend provides a possible way to better control the energy of the plasma arc and expand the application of the plasma arc.