The keyhole GTAW technology: a new welding technology joining quality and productivity

This paper is a literature review regarding the keyhole GTAW technology, which has been developed and first used for industrial applications in Australia. The process enables single pass welding of a wide range of materials including stainless steels, titanium and nickel alloys, up to 12 mm thick. Process parameters (welding current, arc voltage, travel speed, the type of shielding gas and tungsten electrode dimensions) are discussed with regards to keyhole formation and stability. A comparison between standard GTAW and keyhole GTAW is provided for the welding of 12 mm thick stainless steel and titanium, showing the substantial increase in productivity that can be achieved with this new technology. Institut de Soudure has taken part in a European project aimed at assessing the possibilities of the keyhole GTAW technology. (authors)