Mechanical properties of welds in arc welding of similar and dissimilar metals

This study investigates the mechanical performance of similar-dissimilar metal welds using shielded metal arc welding (SMAW) on medium carbon steel (MCS) and stainless steel (SS) square bars, with thicknesses of 10 mm and 12 mm. Mechanical testing (bending, impact tests) revealed that MCS–SS welds absorbed more impact than SS–SS welds but less than MCS–MCS welds. MCS–SS welds also demonstrated higher bending strength than MCS–MCS but lower than SS–SS due to chromium’s strengthening effect in SS. Welding 10–12 mm thicknesses yielded greater impact absorption and bending strength than welding 10–10 mm, although less than welding 12–12 mm thickness. The MCS and SS square bars exhibited angular deflections of 115° and 91°, respectively, and bending stresses of 665 N/mm2 and 1457 N/mm2. Other welded combinations showed angular deflection from 48° to 131° and bending stress from 498 to 858 N/mm2. Our study aims to compare the performance of welds in simultaneous change of metal and thickness in specifically square bars, rather than sheets or plates. Later, an RSM prediction model was developed that showed accuracies of 96.64% and 92.29%, respectively. Lastly, the desirability function identified that welding between 12 mm thick SS bars is the most desirable option.