Arc behaviour and weld formation in gas focusing plasma arc welding

Improving penetrability is a key issue in plasma arc welding (PAW). Increasing plasma energy is one way to improve arc penetrability. Gas focusing plasma arc welding (GF-PAW) platform is self-designed and developed. Role and action mechanism of focusing gas is initially studied. Focusing gas makes no obvious effects on arc pressure distribution and value. Focusing gas changes arc temperature distribution outer orifice, while focusing gas does not affect arc temperature distribution inner orifice. Focusing gas can constrict arc and arc energy increases 210 W with an increase in arc voltage of 1.4 V. GF-PAW can fully penetrate the whole work-piece while PAW can only partially penetrate the work-piece under welding current 150 A. GF-PAW can improve penetrability, and may increase welding speed, and has a potential application in manufacturing.