Properties of electron beam welded SAF 2205 duplex stainless steel

SAF 2205 duplex stainless steel was welded by the electron-beam technique. Optical microscopy, scanning electron microscopy (SEM), tensile impact and potentiodynamic tests were used to examine the microstructure, mechanical and corrosion properties of the weld materials. Metallographic observations showed that the microstructure of the weld metal was characterized by large ferrite grains with intra- and inter-granular austenite. Furthermore, they also revealed that the grain growth in the heat affected zone (HAZ) was restricted when welding with the electron beam technique. The impact tests showed that the weld materials exhibited lower impact strength than that of the parent alloy, the degradation in impact properties of the weld materials being caused by the formation of a small amount of the austenite phase within the weld metal. Potentiodynamic measurements indicated that the weld metal exhibited a lower passive current density than that of the parent alloy when exposed to 1M H2SO4 acid solution.