Measurement and analysis of the welding arc current density and pressure distribution based on split anode method

The distribution characteristics of the current density and arc pressure have an important effect on the welding process. Based on the split anode method, the combined measurement system developed by Beijing University of technology is used to perform high-accuracy data collection of arc current and arc persure. The data is collected from one of the anodes, and some appropriate processes are taken to smooth the data. The distribution characteristics of the arc current density and pressure are obtained by circular segmentation calculation. The tests were carried out on the DC-TIG and DC-plasma by the combined measurement system. The result shows that the current density and the arc pressure increase as the current increasing, the area having the higher current density and arc pressure are also increasing slightly; and the diminution happened on the peak valuation of the current density and arc pressure in the centre while arc length increasing, meanwhile, obvious decrease can be found in the region where current density and arc pressure are high but the distribution radius of the arc extend; although the arc pressure of the plasma arc is obviously larger than the TIG arc, there is no evident impact on the peak valuation of current density in the end of part.