PROPERTIES OF ELECTRON-BEAM WELDED SAF-2205 DUPLEX STAINLESS-STEEL

SAF 2205 duplex stainless steel was welded by the electron-beam techni que. Optical microscopy, scanning electron microscopy (SEM), tensile i mpact and potentiodynamic tests were used to examine the microstructur e, mechanical and corrosion properties of the weld materials. Metallog raphic observations showed that the microstructure of the weld metal w as characterized by large ferrite grains with intra- and inter-granula r austenite. Furthermore, they also revealed that the grain growth in the heat affected zone (HAZ) was restricted when welding with the elec tron beam technique. The impact tests showed that the weld materials e xhibited lower impact strength than that of the parent alloy, the degr adation in impact properties of the weld materials being caused by the formation of a small amount of the austenite phase within the weld me tal. Potentiodynamic measurements indicated that the weld metal exhibi ted a lower passive current density than that of the parent alloy when exposed to 1M H2SO4 acid solution.