Evaluation of Butt Joint Produced by a Hot-Wire CO2 Arc Welding Method

The purpose of this study was to develop a high-efficiency and low-heat-input CO 2 arc-welding process using hot-wire feeding. A previous paper showed that the proposed hot-wire CO 2 arc-welding process has the potential to simultaneously achieve both high efficiency and low heat input. This paper investigated the production of a sound joint with only two welding passes on a butt joint of 20mm-thick steel plates with no defects or unstable welding phenomena using the developed hot-wire CO 2 arc-welding process. Welding condition optimization was investigated using high-speed imaging and cross-sectional observations. The optimized conditions, which were the combinations of the welding current and hot-wire feeding speed as 350A and 7.5m/min, 400A and 5m/min, 450A and 5m/min, 500A and 5m/min, derived to avoid the presence of defects and molten metal precedence, which achieved sound welded joints possessing adequate properties of strength and toughness.