A feasibility study comparing two commercial TIG welding machines for deep penetration

Developing deep penetration TIG welding to produce welds of equal quality to the industrial standard practise of laser-based welding techniques has the potential to lower production complexity and cost. The detrimental effects of the necessary higher currents required to increase penetration depth in conventional TIG welding have been shown to be circumvented through K-TIG and A-TIG techniques. However, prior experimental work on weld pool dynamics in conventional TIG welding in higher current regions has been sparse as TIG welding enhanced through novel techniques provides the best quality welds. This paper is an early feasibility study for novel deep penetration welding techniques motivated by observations made during research done at The University of Sheffield where novel activity in the weld pool was identified during TIG welding with a VBC IE500DHC between 300A – 1000A. This current range is labelled the ‘Red Region’. Understanding the weld pool dynamics in the ‘Red Region’ allows the potential exploration of novel techniques for deep penetration TIG welding. Addressing this, the paper compares the quality of welds produced between 100A and 200A on 316 Stainless Steel by two industrially leading welding machines; the Miller Dynasty 350 and the VBCie 500DHC.