An assessment of impact strength and corrosion behaviour of shielded metal arc welded dissimilar weldments between UNS 31803 and IS 2062 steels

The joining of duplex stainless steel (DSS) to carbon steel (CS) was attempted by shielded metal arc welding, with E2209 and E309 electrodes. The hardness and impact strength of the weld metal produced with E2209 electrodes were found to be better than that obtained with E309. Though the general corrosion resistance of the weld metal produced with E309 was superior in 1 M NaCl solution, they exhibited a higher pitting susceptibility in this test environment. The passivation behaviour of the weld metal with E2209 was observed to be on par with that of the duplex stainless steel base material (DSSBM) in 1 M H2SO4 solution; however, in terms of pitting resistance in 1 M NaCl solution both weld metals were inferior to the DSSBM. Though E309 electrodes are widely employed for producing dissimilar weld joints, based on the observations in the current work, it is concluded that the E2209 electrode is the most suitable consumable for joining DSS to CS.