The effect of cooling rate on the mechanical and corrosion properties of SAF 2205 (UNS 31803) duplex stainless steel welds

Fast water cooling rates in duplex stainless steel (DSS) welds results in a decrease of the width of the ferritization zone to 500 μm compared to 600 μm in the case of air-cooling. Although the austenite volume fraction of the weld zone decreases in water-cooled welds, this fraction of 43% is high enough to provide sound corrosion and mechanical properties for the weld. The hardness of the welded area is affected by the cooling rate, as a direct consequence to the different structures of the welding zones. Water-cooling gives harder weld metal than air cooling, due to the higher volmue fraction of the harder ferrite. Fast water-cooling subsequent to welding decreases also the toughness of the weld.