Exploring the cooling process for residual stress reduction in dissimilar welds

Dissimilar metal welds are currently used in various industry applications; however, a significant number of failures have been reported in these joints due to the existence of large tensile residual stresses induced by arcwelding processes. Hence, it is crucial to reduce or eliminate such residual stresses in dissimilar metal welds. Recently, modern techniques such as CO₂ rapid cooling have received attention by scholars to reduce residual stress in similar metal welds. Nevertheless, the effectivity of this technique has not been explored in dissimilar metal welds. In this paper, the impact of in-situ rapid local cooling in dissimilar metal welds is studied experimentally. The residual stresses of CO₂-cooled welds were measured using the neutron diffraction technique. The effect of rapid cooling on the microstructure of the weld and heat-affected zones were examined. It is shown that for certain cases, in-situ rapid cooling during the arc welding process can minimize tensile residual stresses in dissimilar metal welds.