Abstract
A 3D-numerical model, which predicts both fields of temperature and liquid metal flow in weld pool and time-dependent penetration process by both of spot and moving gas tungsten arc, was developed. In order to examine the validation of the model, penetration shapes in helium gas shielded GTA welding were experimentally and theoretically investigated for two heats of stainless steel having different sulfur contents. Weld penetration of high sulfur stainless steel (250ppm S) was deeper than that of low sulfur stainless steel (10ppm S) for current of 100A in welding speed range up to 10 mm/s. A ratio of depth to width in penetration shape of high sulfur stainless steel decreases with increase of welding speed. Whereas, that of low sulfur stainless steel was almost constant and not dependent on welding speed. It is shown that calculated results agree well with experimental results.
