An investigation of microstructure/property relationships in dissimilar welds between martensitic and austenitic stainless steels

The metallurgical characteristics, tensile, hardness, toughness and corrosion resistance of dissimilar welds between X5CrNi18-10 grade austenitic and X20CrMo13 grade martensitic stainless steel have been evaluated. Both austenitic and duplex stainless steel electrodes were used to join this combination, using multipass manual metal arc welding process. Defect free welds were made with each welding consumable. It was found that the tensile strength of weldment, which was produced by duplex electrode (E2209-17), was slightly lower than that of austenitic electrode (E308L-16). The toughness of the both E2209-17 and E308L-16 deposits was acceptable even at low temperature regardless of heat input. Hardness was increased in both welds made with E2209-17 duplex and E308L-16 austenitic electrode along the X20CrMo13/weld metal fusion boundary due to heat annealing and then following high cooling rate. The pitting corrosion resistance of the weld metal made with E308L-16 and E2209-17 filler metal was found acceptable. Although, heat affected zone in the weldment and X20CrMo13 base metal were affected by electrolytic corrosion. This investigation has shown that both filler metals can be used to join austenitic stainless steel to the martensitic stainless steel.