Abstract
A type 329J1 duplex stainless steel was welded by gas tungsten arc welding in argon-nitrogen gas mixture atmospheres. The penetration depth of weld metal increased with an increase of the nitrogen partial pressure of atmosphere. No porosity was observed in the weld metals. The nitrogen content and microstructure of the weld metal were studied. The nitrogen content increased and the ferrite content decreased with an increase of the nitrogen partial pressure of atmosphere. The ferrite content decreased linearly with an increase of nitrogen content. Fine chromium nitride precipitates were observed in ferrite grains of weld metals, and the amount of precipitates decreased with increases of nitrogen and ferrite contents.
