2205 duplex stainless steels ( DSSs ) are welded in gas tungsten arc welding (GTAW) with the addition of N2 to argon,and the desirable microstracture and properties of the joints are obtained by altering the nitrogen percentage in the shielding gas mixture.The mechanical properties of joints are tested with tensile and microhardness machine,and the joint microstructure is analyzed with scanning electron microscope (SEM) and optical microscope ( OM ),and detrimental phase precipitate is investigated with X-ray diffraction (XRD),respectively.Finally,the corrosion behaviour of joint is also evaluated.Results show that the favorable joint strength and corrosion resistanee can be obtained with appropriate shielding gas mixture in GTAW.No detrimental phase preciphates in the weldment,and the joint tensile fracture obviously presents the characteristic of ductile fracture.